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GFP Tag Polyclonal Antibody

RRID:AB_221569

Antibody ID

AB_221569

Target Antigen

GFP Tag tag

Proper Citation

(Thermo Fisher Scientific Cat# A-11122, RRID:AB_221569)

Clonality

polyclonal antibody

Comments

Applications: ICC (1:200-1:2000), IHC (1:200-1:2000), IF (1:200-1:2000), WB (1:1000-1:3000)

Host Organism

rabbit

Vendor

Thermo Fisher Scientific Go To Vendor

Cat Num

A-11122 also A11122

Publications that use this research resource

Morphological and functional changes in TRPM8-expressing corneal cold thermoreceptor neurons during aging and their impact on tearing in mice.

  • Alcalde I
  • J. Comp. Neurol.
  • 2018 Aug 1

Literature context: ain tearing trigeminal ganglion RRID:AB_221569 RRID: AB_300798 RRID: AB_291637


Abstract:

Morphological and functional alterations of peripheral somatosensory neurons during the aging process lead to a decline of somatosensory perception. Here, we analyze the changes occurring with aging in trigeminal ganglion (TG), TRPM8-expressing cold thermoreceptor neurons innervating the mouse cornea, which participate in the regulation of basal tearing and blinking and have been implicated in the pathogenesis of dry eye disease (DED). TG cell bodies and axonal branches were examined in a mouse line (TRPM8BAC -EYFP) expressing a fluorescent reporter. In 3 months old animals, about 50% of TG cold thermoreceptor neurons were intensely fluorescent, likely providing strongly fluorescent axons and complex corneal nerve terminals with ongoing activity at 34°C and low-threshold, robust responses to cooling. The remaining TRPM8+ corneal axons were weakly fluorescent with nonbeaded axons, sparsely ramified nerve terminals, and exhibited a low-firing rate at 34°C, responding moderately to cooling pulses as do weakly fluorescent TG neurons. In aged (24 months) mice, the number of weakly fluorescent TG neurons was strikingly high while the morphology of TRPM8+ corneal axons changed drastically; 89% were weakly fluorescent, unbranched, and often ending in the basal epithelium. Functionally, 72.5% of aged cold terminals responded as those of young animals, but 27.5% exhibited very low-background activity and abnormal responsiveness to cooling pulses. These morpho-functional changes develop in parallel with an enhancement of tear's basal flow and osmolarity, suggesting that the aberrant sensory inflow to the brain from impaired peripheral cold thermoreceptors contributes to age-induced abnormal tearing and to the high incidence of DED in elderly people.

Funding information:
  • NIH HHS - DP1 OD003958(United States)

Brain Circuits Mediating Opposing Effects on Emotion and Pain.

  • Cai YQ
  • J. Neurosci.
  • 2018 Jul 11

Literature context:


Abstract:

The amygdala is important for processing emotion, including negative emotion such as anxiety and depression induced by chronic pain. Although remarkable progress has been achieved in recent years on amygdala regulation of both negative (fear) and positive (reward) behavioral responses, our current understanding is still limited regarding how the amygdala processes and integrates these negative and positive emotion responses within the amygdala circuits. In this study with optogenetic stimulation of specific brain circuits, we investigated how amygdala circuits regulate negative and positive emotion behaviors, using pain as an emotional assay in male rats. We report here that activation of the excitatory pathway from the parabrachial nucleus (PBN) that relays peripheral pain signals to the central nucleus of amygdala (CeA) is sufficient to cause behaviors of negative emotion including anxiety, depression, and aversion in normal rats. In strong contrast, activation of the excitatory pathway from basolateral amygdala (BLA) that conveys processed corticolimbic signals to CeA dramatically opposes these behaviors of negative emotion, reducing anxiety and depression, and induces behavior of reward. Surprisingly, activating the PBN-CeA pathway to simulate pain signals does not change pain sensitivity itself, but activating the BLA-CeA pathway inhibits basal and sensitized pain. These findings demonstrate that the pain signal conveyed through the PBN-CeA pathway is sufficient to drive negative emotion and that the corticolimbic signal via the BLA-CeA pathway counteracts the negative emotion, suggesting a top-down brain mechanism for cognitive control of negative emotion under stressful environmental conditions such as pain.SIGNIFICANCE STATEMENT It remains unclear how the amygdala circuits integrate both negative and positive emotional responses and the brain circuits that link peripheral pain to negative emotion are largely unknown. Using optogenetic stimulation, this study shows that the excitatory projection from the parabrachial nucleus to the central nucleus of amygdala (CeA) is sufficient to drive behaviors of negative emotion including anxiety, depression, and aversion in rats. Conversely, activation of the excitatory projection from basolateral amygdala to CeA counteracts each of these behaviors of negative emotion. Thus, this study identifies a brain pathway that mediates pain-driven negative emotion and a brain pathway that counteracts these emotion behaviors in a top-down mechanism for brain control of negative emotion.

Funding information:
  • NIDCR NIH HHS - R01 DE025943(United States)
  • NIGMS NIH HHS - T32 GM007270(United States)

Pre-α-pro-GDNF and Pre-β-pro-GDNF Isoforms Are Neuroprotective in the 6-hydroxydopamine Rat Model of Parkinson's Disease.

  • Penttinen AM
  • Front Neurol
  • 2018 Jul 6

Literature context: :"490966","term_text":"A11122"}}


Abstract:

Glial cell line-derived neurotrophic factor (GDNF) is one of the most studied neurotrophic factors. GDNF has two splice isoforms, full-length pre-α-pro-GDNF (α-GDNF) and pre-β-pro-GDNF (β-GDNF), which has a 26 amino acid deletion in the pro-region. Thus far, studies have focused solely on the α-GDNF isoform, and nothing is known about the in vivo effects of the shorter β-GDNF variant. Here we compare for the first time the effects of overexpressed α-GDNF and β-GDNF in non-lesioned rat striatum and the partial 6-hydroxydopamine lesion model of Parkinson's disease. GDNF isoforms were overexpressed with their native pre-pro-sequences in the striatum using an adeno-associated virus (AAV) vector, and the effects on motor performance and dopaminergic phenotype of the nigrostriatal pathway were assessed. In the non-lesioned striatum, both isoforms increased the density of dopamine transporter-positive fibers at 3 weeks after viral vector delivery. Although both isoforms increased the activity of the animals in cylinder assay, only α-GDNF enhanced the use of contralateral paw. Four weeks later, the striatal tyrosine hydroxylase (TH)-immunoreactivity was decreased in both α-GDNF and β-GDNF treated animals. In the neuroprotection assay, both GDNF splice isoforms increased the number of TH-immunoreactive cells in the substantia nigra but did not promote behavioral recovery based on amphetamine-induced rotation or cylinder assays. Thus, the shorter GDNF isoform, β-GDNF, and the full-length α-isoform have comparable neuroprotective efficacy on dopamine neurons of the nigrostriatal circuitry.

Funding information:
  • FIC NIH HHS - R03 TW01236(United States)

Reconfiguration of a Multi-oscillator Network by Light in the Drosophila Circadian Clock.

  • Chatterjee A
  • Curr. Biol.
  • 2018 Jul 9

Literature context: moFisher Cat#A11122; RRID:AB_221569 Mouse monoclonal anti-GFP Therm


Abstract:

The brain clock that drives circadian rhythms of locomotor activity relies on a multi-oscillator neuronal network. In addition to synchronizing the clock with day-night cycles, light also reformats the clock-driven daily activity pattern. How changes in lighting conditions modify the contribution of the different oscillators to remodel the daily activity pattern remains largely unknown. Our data in Drosophila indicate that light readjusts the interactions between oscillators through two different modes. We show that a morning s-LNv > DN1p circuit works in series, whereas two parallel evening circuits are contributed by LNds and other DN1ps. Based on the photic context, the master pacemaker in the s-LNv neurons swaps its enslaved partner-oscillator-LNd in the presence of light or DN1p in the absence of light-to always link up with the most influential phase-determining oscillator. When exposure to light further increases, the light-activated LNd pacemaker becomes independent by decoupling from the s-LNvs. The calibration of coupling by light is layered on a clock-independent network interaction wherein light upregulates the expression of the PDF neuropeptide in the s-LNvs, which inhibits the behavioral output of the DN1p evening oscillator. Thus, light modifies inter-oscillator coupling and clock-independent output-gating to achieve flexibility in the network. It is likely that the light-induced changes in the Drosophila brain circadian network could reveal general principles of adapting to varying environmental cues in any neuronal multi-oscillator system.

Funding information:
  • NIAMS NIH HHS - AR052190(United States)
  • NIGMS NIH HHS - R35 GM118087()

SOXF factors regulate murine satellite cell self-renewal and function through inhibition of β-catenin activity.

  • Alonso-Martin S
  • Elife
  • 2018 Jun 8

Literature context: RRID:AB_221569 1:500


Abstract:

Muscle satellite cells are the primary source of stem cells for postnatal skeletal muscle growth and regeneration. Understanding genetic control of satellite cell formation, maintenance, and acquisition of their stem cell properties is on-going, and we have identified SOXF (SOX7, SOX17, SOX18) transcriptional factors as being induced during satellite cell specification. We demonstrate that SOXF factors regulate satellite cell quiescence, self-renewal and differentiation. Moreover, ablation of Sox17 in the muscle lineage impairs postnatal muscle growth and regeneration. We further determine that activities of SOX7, SOX17 and SOX18 overlap during muscle regeneration, with SOXF transcriptional activity requisite. Finally, we show that SOXF factors also control satellite cell expansion and renewal by directly inhibiting the output of β-catenin activity, including inhibition of Ccnd1 and Axin2. Together, our findings identify a key regulatory function of SoxF genes in muscle stem cells via direct transcriptional control and interaction with canonical Wnt/β-catenin signaling.

Funding information:
  • Agence Nationale de la Recherche - ANR 11 BSV2 017 02()
  • Agence Nationale de la Recherche - ANR-12-BSV1-0038-04()
  • Agence Nationale de la Recherche - ANR-13-BSV1-0011-02()
  • Agence Nationale de la Recherche - ANR-15-CE13-0011-01()
  • Agence Nationale de la Recherche - ANR-15-RHUS-0003()
  • Association Française contre les Myopathies - AFM 16050()
  • Association Française contre les Myopathies - AFM 17865()
  • Association Française contre les Myopathies - TRANSLAMUSCLE 19507()
  • Basque Community - BF106.177()
  • Biotechnology and Biological Sciences Research Council - BB/I017585/1(United Kingdom)
  • Deutsche Forschungsgemeinschaft - GK 1631()
  • Deutsche Forschungsgemeinschaft - KFO192 (Sp1152/8-1)()
  • European Union Sixth and Seventh Framework Program - MYORES and ENDOSTEM # 241440()
  • Fondation pour la Recherche Médicale - DEQ20130326526()
  • Fondation pour la Recherche Médicale - FDT20130928236()
  • FSH Society - 262948-2()
  • FSH Society and BIODESIGN - 262948-2()
  • Horizon 2020 Framework Programme - BIODESIGN (262948-2)()
  • Horizon 2020 Framework Programme - MYORES and ENDOSTEM # 241440()
  • Labex REVIVE - ANR-10-LABX-73()
  • Medical Research Council - MR/PO23215/1()
  • Muscular Dystrophy UK - RA3/3052()

Quantitative Analysis Reveals that Actin and Src-Family Kinases Regulate Nuclear YAP1 and Its Export.

  • Ege N
  • Cell Syst
  • 2018 Jun 27

Literature context: Fisher Scientific Cat# A11122; RRID:AB_221569 Mouse monoclonal IgG1 anti-beta


Abstract:

The transcriptional regulator YAP1 is critical for the pathological activation of fibroblasts. In normal fibroblasts, YAP1 is located in the cytoplasm, while in activated cancer-associated fibroblasts, it is nuclear and promotes the expression of genes required for pro-tumorigenic functions. Here, we investigate the dynamics of YAP1 shuttling in normal and activated fibroblasts, using EYFP-YAP1, quantitative photobleaching methods, and mathematical modeling. Imaging of migrating fibroblasts reveals the tight temporal coupling of cell shape change and altered YAP1 localization. Both 14-3-3 and TEAD binding modulate YAP1 shuttling, but neither affects nuclear import. Instead, we find that YAP1 nuclear accumulation in activated fibroblasts results from Src and actomyosin-dependent suppression of phosphorylated YAP1 export. Finally, we show that nuclear-constrained YAP1, upon XPO1 depletion, remains sensitive to blockade of actomyosin function. Together, these data place nuclear export at the center of YAP1 regulation and indicate that the cytoskeleton can regulate YAP1 within the nucleus.

Funding information:
  • NCRR NIH HHS - R01 RR13601(United States)

A GABAergic Feedback Shapes Dopaminergic Input on the Drosophila Mushroom Body to Promote Appetitive Long-Term Memory.

  • Pavlowsky A
  • Curr. Biol.
  • 2018 Jun 4

Literature context: FP (rabbit)Life TechnologiesCat#A11122Anti-HA (rat)Roche/SigmaCat#1186


Abstract:

Memory consolidation is a crucial step for long-term memory (LTM) storage. However, we still lack a clear picture of how memory consolidation is regulated at the neuronal circuit level. Here, we took advantage of the well-described anatomy of the Drosophila olfactory memory center, the mushroom body (MB), to address this question in the context of appetitive LTM. The MB lobes, which are made by the fascicled axons of the MB intrinsic neurons, are organized into discrete anatomical modules, each covered by the terminals of a defined type of dopaminergic neuron (DAN) and the dendrites of a corresponding type of MB output neuron (MBON). We previously revealed the essential role of one DAN, the MP1 neuron, in the formation of appetitive LTM. The MP1 neuron is anatomically matched to the GABAergic MBON MVP2, which has been attributed feedforward inhibitory functions recently. Here, we used behavior experiments and in vivo imaging to challenge the existence of MP1-MVP2 synapses and investigate their role in appetitive LTM consolidation. We show that MP1 and MVP2 neurons form an anatomically and functionally recurrent circuit, which features a feedback inhibition that regulates consolidation of appetitive memory. This circuit involves two opposite type 1 and type 2 dopamine receptors in MVP2 neurons and the metabotropic GABAB-R1 receptor in MP1 neurons. We propose that this dual-receptor feedback supports a bidirectional self-regulation of MP1 input to the MB. This mechanism displays striking similarities with the mammalian reward system, in which modulation of the dopaminergic signal is primarily assigned to inhibitory neurons.

Funding information:
  • NIAMS NIH HHS - P30 AR053503(United States)

βIV Spectrinopathies Cause Profound Intellectual Disability, Congenital Hypotonia, and Motor Axonal Neuropathy.

  • Wang CC
  • Am. J. Hum. Genet.
  • 2018 Jun 7

Literature context: onal anti-GFP antibody (A11122; RRID:AB_221569) was purchased from Life Techno


Abstract:

βIV spectrin links ankyrinG (AnkG) and clustered ion channels at axon initial segments (AISs) and nodes of Ranvier to the axonal cytoskeleton. Here, we report bi-allelic pathogenic SPTBN4 variants (three homozygous and two compound heterozygous) that cause a severe neurological syndrome that includes congenital hypotonia, intellectual disability, and motor axonal and auditory neuropathy. We introduced these variants into βIV spectrin, expressed these in neurons, and found that 5/7 were loss-of-function variants disrupting AIS localization or abolishing phosphoinositide binding. Nerve biopsies from an individual with a loss-of-function variant had reduced nodal Na+ channels and no nodal KCNQ2 K+ channels. Modeling the disease in mice revealed that although ankyrinR (AnkR) and βI spectrin can cluster Na+ channels and partially compensate for the loss of AnkG and βIV spectrin at nodes of Ranvier, AnkR and βI spectrin cannot cluster KCNQ2- and KCNQ3-subunit-containing K+ channels. Our findings define a class of spectrinopathies and reveal the molecular pathologies causing nervous-system dysfunction.

Funding information:
  • NIAID NIH HHS - U19 AI082714()
  • NIAMS NIH HHS - R01 AR056360()
  • NIAMS NIH HHS - R01 AR063124()
  • NICHD NIH HHS - R01 HD064610(United States)
  • NIGMS NIH HHS - P30 GM110766()
  • NINDS NIH HHS - K12 NS049453()
  • NINDS NIH HHS - R01 NS044916()
  • NINDS NIH HHS - R01 NS069688()
  • NINDS NIH HHS - R37 NS044916()

The Polycomb-Dependent Epigenome Controls β Cell Dysfunction, Dedifferentiation, and Diabetes.

  • Lu TT
  • Cell Metab.
  • 2018 Jun 5

Literature context: fic Cat#A-11122; RRID:AB_221569 Biological Samples


Abstract:

To date, it remains largely unclear to what extent chromatin machinery contributes to the susceptibility and progression of complex diseases. Here, we combine deep epigenome mapping with single-cell transcriptomics to mine for evidence of chromatin dysregulation in type 2 diabetes. We find two chromatin-state signatures that track β cell dysfunction in mice and humans: ectopic activation of bivalent Polycomb-silenced domains and loss of expression at an epigenomically unique class of lineage-defining genes. β cell-specific Polycomb (Eed/PRC2) loss of function in mice triggers diabetes-mimicking transcriptional signatures and highly penetrant, hyperglycemia-independent dedifferentiation, indicating that PRC2 dysregulation contributes to disease. The work provides novel resources for exploring β cell transcriptional regulation and identifies PRC2 as necessary for long-term maintenance of β cell identity. Importantly, the data suggest a two-hit (chromatin and hyperglycemia) model for loss of β cell identity in diabetes.

Funding information:
  • NIAID NIH HHS - R01 AI084808(United States)

A Critical Neurodevelopmental Role for L-Type Voltage-Gated Calcium Channels in Neurite Extension and Radial Migration.

  • Kamijo S
  • J. Neurosci.
  • 2018 Jun 13

Literature context: ermo Fisher Scientific, A11122, RRID:AB_221569), rat monoclonal anti-GFP (Naca


Abstract:

Despite many association studies linking gene polymorphisms and mutations of L-type voltage-gated Ca2+ channels (VGCCs) in neurodevelopmental disorders such as autism and schizophrenia, the roles of specific L-type VGCC during brain development remain unclear. Calcium signaling has been shown to be essential for neurodevelopmental processes such as sculpting of neurites, functional wiring, and fine tuning of growing networks. To investigate this relationship, we performed submembraneous calcium imaging using a membrane-tethered genetically encoded calcium indicator (GECI) Lck-G-CaMP7. We successfully recorded spontaneous regenerative calcium transients (SRCaTs) in developing mouse excitatory cortical neurons prepared from both sexes before synapse formation. SRCaTs originated locally in immature neurites independently of somatic calcium rises and were significantly more elevated in the axons than in dendrites. SRCaTs were not blocked by tetrodoxin, a Na+ channel blocker, but were strongly inhibited by hyperpolarization, suggesting a voltage-dependent source. Pharmacological and genetic manipulations revealed the critical importance of the Cav1.2 (CACNA1C) pore-forming subunit of L-type VGCCs, which were indeed expressed in immature mouse brains. Consistently, knocking out Cav1.2 resulted in significant alterations of neurite outgrowth. Furthermore, expression of a gain-of-function Cav1.2 mutant found in Timothy syndrome, an autosomal dominant multisystem disorder exhibiting syndromic autism, resulted in impaired radial migration of layer 2/3 excitatory neurons, whereas postnatal abrogation of Cav1.2 enhancement could rescue cortical malformation. Together, these lines of evidence suggest a critical role for spontaneous opening of L-type VGCCs in neural development and corticogenesis and indicate that L-type VGCCs might constitute a perinatal therapeutic target for neuropsychiatric calciochannelopathies.SIGNIFICANCE STATEMENT Despite many association studies linking gene polymorphisms and mutations of L-type voltage-gated Ca2+ channels (VGCCs) in neurodevelopmental disorders such as autism and schizophrenia, the roles of specific L-type VGCCs during brain development remain unclear. We here combined the latest Ca2+ indicator technology, quantitative pharmacology, and in utero electroporation and found a hitherto unsuspected role for L-type VGCCs in determining the Ca2+ signaling landscape of mouse immature neurons. We found that malfunctional L-type VGCCs in immature neurons before birth might cause errors in neuritic growth and cortical migration. Interestingly, the retarded corticogenesis phenotype was rescued by postnatal correction of L-type VGCC signal aberration. These findings suggest that L-type VGCCs might constitute a perinatal therapeutic target for neurodevelopment-associated psychiatric disorders.

Funding information:
  • Howard Hughes Medical Institute - R01HD041900(United States)

Targeting Kruppel-like Factor 9 in Excitatory Neurons Protects against Chronic Stress-Induced Impairments in Dendritic Spines and Fear Responses.

  • Besnard A
  • Cell Rep
  • 2018 Jun 12

Literature context: 2, 1:500 [Antibodyregistry.org: RRID:AB_221569]) was carried out with shaking


Abstract:

Stress exposure is associated with the pathogenesis of psychiatric disorders, including post-traumatic stress disorder (PTSD) and major depressive disorder (MDD). Here, we show in rodents that chronic stress exposure rapidly and transiently elevates hippocampal expression of Kruppel-like factor 9 (Klf9). Inducible genetic silencing of Klf9 expression in excitatory forebrain neurons in adulthood prior to, but not after, onset of stressor prevented chronic restraint stress (CRS)-induced potentiation of contextual fear acquisition in female mice and chronic corticosterone (CORT) exposure-induced fear generalization in male mice. Klf9 silencing prevented chronic CORT and CRS induced enlargement of dendritic spines in the ventral hippocampus of male and female mice, respectively. KLF9 mRNA density was increased in the anterior dentate gyrus of women, but not men, with more severe recent stressful life events and increased mortality. Thus, Klf9 functions as a stress-responsive transcription factor that mediates circuit and behavioral resilience in a sex-specific manner.

Funding information:
  • NCI NIH HHS - R01 CA159811(United States)

Phospholipase PLA2G6, a Parkinsonism-Associated Gene, Affects Vps26 and Vps35, Retromer Function, and Ceramide Levels, Similar to α-Synuclein Gain.

  • Lin G
  • Cell Metab.
  • 2018 Jun 7

Literature context: Technologies RRID:AB_221569 rat anti-Elav DSHB AB_528218


Abstract:

Mutations in PLA2G6 (PARK14) cause neurodegenerative disorders in humans, including autosomal recessive neuroaxonal dystrophy and early-onset parkinsonism. We show that loss of iPLA2-VIA, the fly homolog of PLA2G6, reduces lifespan, impairs synaptic transmission, and causes neurodegeneration. Phospholipases typically hydrolyze glycerol phospholipids, but loss of iPLA2-VIA does not affect the phospholipid composition of brain tissue but rather causes an elevation in ceramides. Reducing ceramides with drugs, including myriocin or desipramine, alleviates lysosomal stress and suppresses neurodegeneration. iPLA2-VIA binds the retromer subunits Vps35 and Vps26 and enhances retromer function to promote protein and lipid recycling. Loss of iPLA2-VIA impairs retromer function, leading to a progressive increase in ceramide. This induces a positive feedback loop that affects membrane fluidity and impairs retromer function and neuronal function. Similar defects are observed upon loss of vps26 or vps35 or overexpression of α-synuclein, indicating that these defects may be common in Parkinson disease.

Funding information:
  • NCI NIH HHS - R01 CA130893(United States)

VIP-immunoreactive interneurons within circuits of the mouse basolateral amygdala.

  • Rhomberg T
  • J. Neurosci.
  • 2018 Jun 28

Literature context: A11122 1356608 Rabbit 1:1.000 RRID:AB_221569 NPY Synaptic Systems 394 004 39


Abstract:

In cortical structures, principal cell activity is tightly regulated by different GABAergic interneurons (INs). In particular, vasoactive intestinal polypeptide-expressing (VIP+) INs innervate preferentially other INs, providing a structural basis for temporal disinhibition of principal cells. However, relatively little is known about VIP+ INs in the amygdaloid basolateral complex (BLA). In this study, we report that VIP+ INs have a variable density in the distinct subdivisions of the mouse BLA. Based on different anatomical, neurochemical and electrophysiological criteria, VIP+ INs could be identified as interneuron-selective INs and basket cells expressing CB1 cannabinoid receptors. Whole-cell recordings of VIP+ interneuron-selective INs revealed 3 different spiking patterns, which did not associate with the expression of calretinin. Genetic targeting combined with optogenetics and in vitro recordings allowed us to identify several types of BLA INs innervated by VIP+ INs, including other interneuron-selective INs, basket and neurogliaform cells. Moreover, light stimulation of VIP+ basket cell axon terminals, characterized by CB1 sensitivity, evoked IPSPs in ∼20% of principal neurons. Finally, we show that VIP+ INs receive a dense innervation from both GABAergic, although only 10% from other VIP+ INs, and distinct glutamatergic inputs, identified by their expression of different vesicular glutamate transporters.In conclusion, our study provides a wide-range analysis of single-cell properties of VIP+ INs in the mouse BLA and of their intrinsic and extrinsic connectivity. Our results reinforce the knowledge that VIP+ INs are structurally and functionally heterogeneous and that this heterogeneity could mediate different roles in amygdala-dependent functions.Significance statement:We provide the first comprehensive analysis of the distribution of VIP+ interneurons across the entire mouse BLA, as well as of their morphological and physiological properties. VIP+ interneurons in the neocortex preferentially target other interneurons to form a disinhibitory network that facilitates principal cell firing. Our study is the first to demonstrate the presence of such a disinhibitory circuitry in the BLA. We observed structural and functional heterogeneity of these INs and characterized their input/output connectivity. We also identified several types of BLA interneurons postsynaptic to VIP+ INs, whose inhibition may provide a temporal window for principal cell firing and facilitate associative plasticity, e.g. in fear learning. Disinhibition, thus, is emerging as a general mechanism, not limited to the neocortex.

Funding information:
  • NIGMS NIH HHS - GM055962(United States)

The functional organization of descending sensory-motor pathways in Drosophila.

  • Namiki S
  • Elife
  • 2018 Jun 26

Literature context: RRID:AB_221569


Abstract:

In most animals, the brain controls the body via a set of descending neurons (DNs) that traverse the neck. DN activity activates, maintains or modulates locomotion and other behaviors. Individual DNs have been well-studied in species from insects to primates, but little is known about overall connectivity patterns across the DN population. We systematically investigated DN anatomy in Drosophila melanogaster and created over 100 transgenic lines targeting individual cell types. We identified roughly half of all Drosophila DNs and comprehensively map connectivity between sensory and motor neuropils in the brain and nerve cord, respectively. We find the nerve cord is a layered system of neuropils reflecting the fly's capability for two largely independent means of locomotion -- walking and flight -- using distinct sets of appendages. Our results reveal the basic functional map of descending pathways in flies and provide tools for systematic interrogation of neural circuits.

Funding information:
  • NCI NIH HHS - K99/R00 CA158055-01(United States)

How Diverse Retinal Functions Arise from Feedback at the First Visual Synapse.

  • Drinnenberg A
  • Neuron
  • 2018 Jun 15

Literature context: y Life Tech Cat #A-11122; RRID:AB_221569 Goat anti-ChAT primary antibody


Abstract:

Many brain regions contain local interneurons of distinct types. How does an interneuron type contribute to the input-output transformations of a given brain region? We addressed this question in the mouse retina by chemogenetically perturbing horizontal cells, an interneuron type providing feedback at the first visual synapse, while monitoring the light-driven spiking activity in thousands of ganglion cells, the retinal output neurons. We uncovered six reversible perturbation-induced effects in the response dynamics and response range of ganglion cells. The effects were enhancing or suppressive, occurred in different response epochs, and depended on the ganglion cell type. A computational model of the retinal circuitry reproduced all perturbation-induced effects and led us to assign specific functions to horizontal cells with respect to different ganglion cell types. Our combined experimental and theoretical work reveals how a single interneuron type can differentially shape the dynamical properties of distinct output channels of a brain region.

Funding information:
  • European Research Council - 233083(International)

Heterochromatin-Encoded Satellite RNAs Induce Breast Cancer.

  • Zhu Q
  • Mol. Cell
  • 2018 Jun 7

Literature context: -11122, RRID:AB_221569 rabbit anti-cytokeratin 5 Abcam


Abstract:

Heterochromatic repetitive satellite RNAs are extensively transcribed in a variety of human cancers, including BRCA1 mutant breast cancer. Aberrant expression of satellite RNAs in cultured cells induces the DNA damage response, activates cell cycle checkpoints, and causes defects in chromosome segregation. However, the mechanism by which satellite RNA expression leads to genomic instability is not well understood. Here we provide evidence that increased levels of satellite RNAs in mammary glands induce tumor formation in mice. Using mass spectrometry, we further show that genomic instability induced by satellite RNAs occurs through interactions with BRCA1-associated protein networks required for the stabilization of DNA replication forks. Additionally, de-stabilized replication forks likely promote the formation of RNA-DNA hybrids in cells expressing satellite RNAs. These studies lay the foundation for developing novel therapeutic strategies that block the effects of non-coding satellite RNAs in cancer cells.

Funding information:
  • NCI NIH HHS - R01 CA080100()
  • NIAID NIH HHS - R01 AI015066(United States)

Optogenetic Editing Reveals the Hierarchical Organization of Learned Action Sequences.

  • Geddes CE
  • Cell
  • 2018 Jun 28

Literature context: RRID:AB_221569 AlexaFluor 647 Donkey anti-Rabb


Abstract:

The organization of action into sequences underlies complex behaviors that are essential for organismal survival and reproduction. Despite extensive studies of innate sequences in relation to central pattern generators, how learned action sequences are controlled and whether they are organized as a chain or a hierarchy remain largely unknown. By training mice to perform heterogeneous action sequences, we demonstrate that striatal direct and indirect pathways preferentially encode different behavioral levels of sequence structure. State-dependent closed-loop optogenetic stimulation of the striatal direct pathway can selectively insert a single action element into the sequence without disrupting the overall sequence length. Optogenetic manipulation of the striatal indirect pathway completely removes the ongoing subsequence while leaving the following subsequence to be executed with the appropriate timing and length. These results suggest that learned action sequences are not organized in a serial but rather a hierarchical structure that is distinctly controlled by basal ganglia pathways.

Funding information:
  • Medical Research Council - G1100312(United Kingdom)

Hippocampal 5-HT Input Regulates Memory Formation and Schaffer Collateral Excitation.

  • Teixeira CM
  • Neuron
  • 2018 Jun 6

Literature context: Fischer Scientific Cat# A11122; RRID:AB_221569 Goat-anti-5-HT Abcam Cat# ab660


Abstract:

The efficacy and duration of memory storage is regulated by neuromodulatory transmitter actions. While the modulatory transmitter serotonin (5-HT) plays an important role in implicit forms of memory in the invertebrate Aplysia, its function in explicit memory mediated by the mammalian hippocampus is less clear. Specifically, the consequences elicited by the spatio-temporal gradient of endogenous 5-HT release are not known. Here we applied optogenetic techniques in mice to gain insight into this fundamental biological process. We find that activation of serotonergic terminals in the hippocampal CA1 region both potentiates excitatory transmission at CA3-to-CA1 synapses and enhances spatial memory. Conversely, optogenetic silencing of CA1 5-HT terminals inhibits spatial memory. We furthermore find that synaptic potentiation is mediated by 5-HT4 receptors and that systemic modulation of 5-HT4 receptor function can bidirectionally impact memory formation. Collectively, these data reveal powerful modulatory influence of serotonergic synaptic input on hippocampal function and memory formation.

Funding information:
  • NCI NIH HHS - CA-41223(United States)

Dual Requirement of CHD8 for Chromatin Landscape Establishment and Histone Methyltransferase Recruitment to Promote CNS Myelination and Repair.

  • Zhao C
  • Dev. Cell
  • 2018 Jun 18

Literature context: s Cat# A-11122, RRID:AB_221569 Rabbit Monoclonal anti-Sox10 Ab


Abstract:

Disruptive mutations in chromatin remodeler CHD8 cause autism spectrum disorders, exhibiting widespread white matter abnormalities; however, the underlying mechanisms remain elusive. We show that cell-type specific Chd8 deletion in oligodendrocyte progenitors, but not in neurons, results in myelination defects, revealing a cell-intrinsic dependence on CHD8 for oligodendrocyte lineage development, myelination and post-injury remyelination. CHD8 activates expression of BRG1-associated SWI/SNF complexes that in turn activate CHD7, thus initiating a successive chromatin remodeling cascade that orchestrates oligodendrocyte lineage progression. Genomic occupancy analyses reveal that CHD8 establishes an accessible chromatin landscape, and recruits MLL/KMT2 histone methyltransferase complexes distinctively around proximal promoters to promote oligodendrocyte differentiation. Inhibition of histone demethylase activity partially rescues myelination defects of CHD8-deficient mutants. Our data indicate that CHD8 exhibits a dual function through inducing a cascade of chromatin reprogramming and recruiting H3K4 histone methyltransferases to establish oligodendrocyte identity, suggesting potential strategies of therapeutic intervention for CHD8-associated white matter defects.

Funding information:
  • NIMH NIH HHS - R01 MH087592(United States)

ER Lipid Defects in Neuropeptidergic Neurons Impair Sleep Patterns in Parkinson's Disease.

  • Valadas JS
  • Neuron
  • 2018 Jun 27

Literature context: in (GFP) Invitrogen Cat#A-11122 RRID:AB_221569 anti-Vasoactive Intestinal Pept


Abstract:

Parkinson's disease patients report disturbed sleep patterns long before motor dysfunction. Here, in parkin and pink1 models, we identify circadian rhythm and sleep pattern defects and map these to specific neuropeptidergic neurons in fly models and in hypothalamic neurons differentiated from patient induced pluripotent stem cells (iPSCs). Parkin and Pink1 control the clearance of mitochondria by protein ubiquitination. Although we do not observe major defects in mitochondria of mutant neuropeptidergic neurons, we do find an excess of endoplasmic reticulum-mitochondrial contacts. These excessive contact sites cause abnormal lipid trafficking that depletes phosphatidylserine from the endoplasmic reticulum (ER) and disrupts the production of neuropeptide-containing vesicles. Feeding mutant animals phosphatidylserine rescues neuropeptidergic vesicle production and acutely restores normal sleep patterns in mutant animals. Hence, sleep patterns and circadian disturbances in Parkinson's disease models are explained by excessive ER-mitochondrial contacts, and blocking their formation or increasing phosphatidylserine levels rescues the defects in vivo.

Funding information:
  • NIGMS NIH HHS - GM073874(United States)

Ejaculation Induced by the Activation of Crz Neurons Is Rewarding to Drosophila Males.

  • Zer-Krispil S
  • Curr. Biol.
  • 2018 May 7

Literature context: ar probes Cat# A11122 RRID:AB_221569 Alexa Fluor 568 goat polyclonal


Abstract:

The reward system is a collection of circuits that reinforce behaviors necessary for survival [1, 2]. Given the importance of reproduction for survival, actions that promote successful mating induce pleasurable feeling and are positively reinforced [3, 4]. This principle is conserved in Drosophila, where successful copulation is naturally rewarding to male flies, induces long-term appetitive memories [5], increases brain levels of neuropeptide F (NPF, the fly homolog of neuropeptide Y), and prevents ethanol, known otherwise as rewarding to flies [6, 7], from being rewarding [5]. It is not clear which of the multiple sensory and motor responses performed during mating induces perception of reward. Sexual interactions with female flies that do not reach copulation are not sufficient to reduce ethanol consumption [5], suggesting that only successful mating encounters are rewarding. Here, we uncoupled the initial steps of mating from its final steps and tested the ability of ejaculation to mimic the rewarding value of full copulation. We induced ejaculation by activating neurons that express the neuropeptide corazonin (CRZ) [8] and subsequently measured different aspects of reward. We show that activating Crz-expressing neurons is rewarding to male flies, as they choose to reside in a zone that triggers optogenetic stimulation of Crz neurons and display conditioned preference for an odor paired with the activation. Reminiscent of successful mating, repeated activation of Crz neurons increases npf levels and reduces ethanol consumption. Our results demonstrate that ejaculation stimulated by Crz/Crz-receptor signaling serves as an essential part of the mating reward mechanism in Drosophila. VIDEO ABSTRACT.

Funding information:
  • NIH HHS - DP2 OD007417(United States)

Anatomic and Physiologic Heterogeneity of Subgroup-A Auditory Sensory Neurons in Fruit Flies.

  • Ishikawa Y
  • Front Neural Circuits
  • 2018 May 2

Literature context: itrogen, La Jolla, CA, #A11122, RRID:AB_221569, used at 1:1,000 dilution) and


Abstract:

The antennal ear of the fruit fly detects acoustic signals in intraspecific communication, such as the courtship song and agonistic sounds. Among the five subgroups of mechanosensory neurons in the fly ear, subgroup-A neurons respond maximally to vibrations over a wide frequency range between 100 and 1,200 Hz. The functional organization of the neural circuit comprised of subgroup-A neurons, however, remains largely unknown. In the present study, we used 11 GAL4 strains that selectively label subgroup-A neurons and explored the diversity of subgroup-A neurons by combining single-cell anatomic analysis and Ca2+ imaging. Our findings indicate that the subgroup-A neurons that project into various combinations of subareas in the brain are more anatomically diverse than previously described. Subgroup-A neurons were also physiologically diverse, and some types were tuned to a narrow frequency range, suggesting that the response of subgroup-A neurons to sounds of a wide frequency range is due to the existence of several types of subgroup-A neurons. Further, we found that an auditory behavioral response to the courtship song of flies was attenuated when most subgroup-A neurons were silenced. Together, these findings characterize the heterogeneous functional organization of subgroup-A neurons, which might facilitate species-specific acoustic signal detection.

RNP-Granule Assembly via Ataxin-2 Disordered Domains Is Required for Long-Term Memory and Neurodegeneration.

  • Bakthavachalu B
  • Neuron
  • 2018 May 16

Literature context: abbit anti-GFP Molecular probes RRID:AB_221569 Chicken anti-GFP Abcam RRID: AB


Abstract:

Human Ataxin-2 is implicated in the cause and progression of amyotrophic lateral sclerosis (ALS) and type 2 spinocerebellar ataxia (SCA-2). In Drosophila, a conserved atx2 gene is essential for animal survival as well as for normal RNP-granule assembly, translational control, and long-term habituation. Like its human homolog, Drosophila Ataxin-2 (Atx2) contains polyQ repeats and additional intrinsically disordered regions (IDRs). We demonstrate that Atx2 IDRs, which are capable of mediating liquid-liquid phase transitions in vitro, are essential for efficient formation of neuronal mRNP assemblies in vivo. Remarkably, ΔIDR mutants that lack neuronal RNP granules show normal animal development, survival, and fertility. However, they show defects in long-term memory formation/consolidation as well as in C9ORF72 dipeptide repeat or FUS-induced neurodegeneration. Together, our findings demonstrate (1) that higher-order mRNP assemblies contribute to long-term neuronal plasticity and memory, and (2) that a targeted reduction in RNP-granule formation efficiency can alleviate specific forms of neurodegeneration.

Funding information:
  • NCI NIH HHS - 5K12 CA 076931(United States)

Schaffer Collateral Inputs to CA1 Excitatory and Inhibitory Neurons Follow Different Connectivity Rules.

  • Kwon O
  • J. Neurosci.
  • 2018 May 30

Literature context: t anti-GFP (Invitrogen, 1:1000; RRID:AB_221569); rabbit anti-DsRed (Clontech,


Abstract:

Neural circuits, governed by a complex interplay between excitatory and inhibitory neurons, are the substrate for information processing, and the organization of synaptic connectivity in neural network is an important determinant of circuit function. Here, we analyzed the fine structure of connectivity in hippocampal CA1 excitatory and inhibitory neurons innervated by Schaffer collaterals (SCs) using mGRASP in male mice. Our previous study revealed spatially structured synaptic connectivity between CA3 and CA1 pyramidal cells (PCs). Surprisingly, parvalbumin-positive interneurons (PVs) showed a significantly more random pattern spatial structure. Notably, application of Peters' rule for synapse prediction by random overlap between axons and dendrites enhanced structured connectivity in PCs, but, by contrast, made the connectivity pattern in PVs more random. In addition, PCs in a deep sublayer of striatum pyramidale appeared more highly structured than PCs in superficial layers, and little or no sublayer specificity was found in PVs. Our results show that CA1 excitatory PCs and inhibitory PVs innervated by the same SC inputs follow different connectivity rules. The different organizations of fine scale structured connectivity in hippocampal excitatory and inhibitory neurons provide important insights into the development and functions of neural networks.SIGNIFICANCE STATEMENT Understanding how neural circuits generate behavior is one of the central goals of neuroscience. An important component of this endeavor is the mapping of fine-scale connection patterns that underlie, and help us infer, signal processing in the brain. Here, using our recently developed synapse detection technology (mGRASP and neuTube), we provide detailed profiles of synaptic connectivity in excitatory (CA1 pyramidal) and inhibitory (CA1 parvalbumin-positive) neurons innervated by the same presynaptic inputs (CA3 Schaffer collaterals). Our results reveal that these two types of CA1 neurons follow different connectivity patterns. Our new evidence for differently structured connectivity at a fine scale in hippocampal excitatory and inhibitory neurons provides a better understanding of hippocampal networks and will guide theoretical and experimental studies.

Funding information:
  • Wellcome Trust - G0800784(United Kingdom)

Distinct Accumbens Shell Output Pathways Promote versus Prevent Relapse to Alcohol Seeking.

  • Gibson GD
  • Neuron
  • 2018 May 2

Literature context: oFisher Scientific Cat#AA11122; RRID:AB_221569 Rabbit anti-mCherry Polyclonal


Abstract:

Contexts exert bi-directional control over relapse to drug seeking. Contexts associated with drug self-administration promote relapse, whereas contexts associated with the absence of self-administration protect against relapse. The nucleus accumbens shell (AcbSh) is a key brain region determining these roles of context. However, the specific cell types, and projections, by which AcbSh serves these dual roles are unknown. Here, we show that contextual control over relapse and abstinence is embedded within distinct output circuits of dopamine 1 receptor (Drd1) expressing AcbSh neurons. We report anatomical and functional segregation of Drd1 AcbSh output pathways during context-induced reinstatement and extinction of alcohol seeking. The AcbSh→ventral tegmental area (VTA) pathway promotes relapse via projections to VTA Gad1 neurons. The AcbSh→lateral hypothalamus (LH) pathway promotes extinction via projections to LH Gad1 neurons. Targeting these opposing AcbSh circuit contributions may reduce propensity to relapse to, and promote abstinence from, drug use.

Funding information:
  • NIGMS NIH HHS - F31 GM095289-01(United States)

Corticospinal Circuits from the Sensory and Motor Cortices Differentially Regulate Skilled Movements through Distinct Spinal Interneurons.

  • Ueno M
  • Cell Rep
  • 2018 May 1

Literature context: trogen A11122; RRID:AB_221569 Rat monoclonal anti-GFP Nacalai


Abstract:

Little is known about the organizational and functional connectivity of the corticospinal (CS) circuits that are essential for voluntary movement. Here, we map the connectivity between CS neurons in the forelimb motor and sensory cortices and various spinal interneurons, demonstrating that distinct CS-interneuron circuits control specific aspects of skilled movements. CS fibers originating in the mouse motor cortex directly synapse onto premotor interneurons, including those expressing Chx10. Lesions of the motor cortex or silencing of spinal Chx10+ interneurons produces deficits in skilled reaching. In contrast, CS neurons in the sensory cortex do not synapse directly onto premotor interneurons, and they preferentially connect to Vglut3+ spinal interneurons. Lesions to the sensory cortex or inhibition of Vglut3+ interneurons cause deficits in food pellet release movements in goal-oriented tasks. These findings reveal that CS neurons in the motor and sensory cortices differentially control skilled movements through distinct CS-spinal interneuron circuits.

Funding information:
  • NIA NIH HHS - R01 AG023806(United States)

The Circadian Clock Sets the Time of DNA Replication Licensing to Regulate Growth in Arabidopsis.

  • Fung-Uceda J
  • Dev. Cell
  • 2018 Apr 9

Literature context: r Scientific Cat#A-11122-100uL; RRID:AB_221569 Bacterial and Virus Strains


Abstract:

The circadian clock and cell cycle as separate pathways have been well documented in plants. Elucidating whether these two oscillators are connected is critical for understanding plant growth. We found that a slow-running circadian clock decelerates the cell cycle and, conversely, a fast clock speeds it up. The clock component TOC1 safeguards the G1-to-S transition and controls the timing of the mitotic cycle at early stages of leaf development. TOC1 also regulates somatic ploidy at later stages of leaf development and in hypocotyl cells. The S-phase is shorter and delayed in TOC1 overexpressing plants, which correlates with the diurnal repression of the DNA replication licensing gene CDC6 through binding of TOC1 to the CDC6 promoter. The slow cell-cycle pace in TOC1-ox also results in delayed tumor progression in inflorescence stalks. Thus, TOC1 sets the time of the DNA pre-replicative machinery to control plant growth in resonance with the environment.

Funding information:
  • Biotechnology and Biological Sciences Research Council - BBS/E/J/00000603(United Kingdom)

Functional Divergence of Delta and Mu Opioid Receptor Organization in CNS Pain Circuits.

  • Wang D
  • Neuron
  • 2018 Apr 4

Literature context: s Cat# A-11122; RRID:AB_221569 Anti-RFP Rabbit Abcam Cat# ab62


Abstract:

Cellular interactions between delta and mu opioid receptors (DORs and MORs), including heteromerization, are thought to regulate opioid analgesia. However, the identity of the nociceptive neurons in which such interactions could occur in vivo remains elusive. Here we show that DOR-MOR co-expression is limited to small populations of excitatory interneurons and projection neurons in the spinal cord dorsal horn and unexpectedly predominates in ventral horn motor circuits. Similarly, DOR-MOR co-expression is rare in parabrachial, amygdalar, and cortical brain regions processing nociceptive information. We further demonstrate that in the discrete DOR-MOR co-expressing nociceptive neurons, the two receptors internalize and function independently. Finally, conditional knockout experiments revealed that DORs selectively regulate mechanical pain by controlling the excitability of somatostatin-positive dorsal horn interneurons. Collectively, our results illuminate the functional organization of DORs and MORs in CNS pain circuits and reappraise the importance of DOR-MOR cellular interactions for developing novel opioid analgesics.

Funding information:
  • NCI NIH HHS - P30 CA042014(United States)

Vaginal estrogen: a dual-edged sword in postoperative healing of the vaginal wall.

  • Ripperda CM
  • Menopause
  • 2018 Apr 17

Literature context: g was obtained from Invitrogen (RRID AB_10073917). After slides were thawed unde


Abstract:

OBJECTIVE: Reconstructive surgery for pelvic organ prolapse is plagued with high failure rates possibly due to impaired healing or regeneration of the vaginal wall. Here, we tested the hypothesis that postoperative administration of local estrogen, direct injection of mesenchymal stem cells (MSCs), or both lead to improved wound healing of the injured vagina in a menopausal rat model. METHODS: Ovariectomized rats underwent surgical injury to the posterior vaginal wall and were randomized to treatment with placebo (n = 41), estrogen cream (n = 47), direct injection of MSCs (n = 39), or both (n = 43). RESULTS: MSCs did not survive after injection and had no appreciable effects on healing of the vaginal wall. Acute postoperative administration of vaginal estrogen altered the response of the vaginal wall to injury with decreased stiffness, decreased collagen content, and decreased expression of transcripts for matrix components in the stromal compartment. Conversely, vaginal estrogen resulted in marked proliferation of the epithelial layer and increased expression of genes related to epithelial barrier function and protease inhibition. Transcripts for genes involved in chronic inflammation and adaptive immunity were also down-regulated in the estrogenized epithelium. CONCLUSIONS: Collectively, these data indicate that, in contrast to the reported positive effects of preoperative estrogen on the uninjured vagina, acute administration of postoperative vaginal estrogen has adverse effects on the early phase of healing of the stromal layer. In contrast, postoperative estrogen plays a positive role in healing of the vaginal epithelium after injury.

Funding information:
  • NIA NIH HHS - R01 AG028048()
  • NIA NIH HHS - R01 AG047290()
  • NICHD NIH HHS - R01 HD064824()

A Basal Ganglia Circuit Sufficient to Guide Birdsong Learning.

  • Xiao L
  • Neuron
  • 2018 Apr 4

Literature context: : AB_221569 mouse anti-GFP Invitrogen RRID:


Abstract:

Learning vocal behaviors, like speech and birdsong, is thought to rely on continued performance evaluation. Whether candidate performance evaluation circuits in the brain are sufficient to guide vocal learning is not known. Here, we test the sufficiency of VTA projections to the vocal basal ganglia in singing zebra finches, a songbird species that learns to produce a complex and stereotyped multi-syllabic courtship song during development. We optogenetically manipulate VTA axon terminals in singing birds contingent on how the pitch of an individual song syllable is naturally performed. We find that optical inhibition and excitation of VTA terminals are each sufficient to reliably guide learned changes in song. Inhibition and excitation have opponent effects on future performances of targeted song syllables, consistent with positive and negative reinforcement of performance outcomes. These findings define a central role for reinforcement mechanisms in learning vocalizations and demonstrate minimal circuit elements for learning vocal behaviors. VIDEO ABSTRACT.

Funding information:
  • Intramural NIH HHS - Z01 ES090080-11(United States)
  • NIDA NIH HHS - R21 DA042362()
  • NIDCD NIH HHS - R01 DC014364()
  • NIMH NIH HHS - R03 MH111319()
  • NINDS NIH HHS - R01 NS102488()

A Hypothalamic Midbrain Pathway Essential for Driving Maternal Behaviors.

  • Fang YY
  • Neuron
  • 2018 Apr 4

Literature context: Life Technologies Cat# A11122; RRID:AB_221569 Donkey anti-rabbit Dylight 488


Abstract:

Maternal behaviors are essential for the survival of the young. Previous studies implicated the medial preoptic area (MPOA) as an important region for maternal behaviors, but details of the maternal circuit remain incompletely understood. Here we identify estrogen receptor alpha (Esr1)-expressing cells in the MPOA as key mediators of pup approach and retrieval. Reversible inactivation of MPOAEsr1+ cells impairs those behaviors, whereas optogenetic activation induces immediate pup retrieval. In vivo recordings demonstrate preferential activation of MPOAEsr1+ cells during maternal behaviors and changes in MPOA cell responses across reproductive states. Furthermore, channelrhodopsin-assisted circuit mapping reveals a strong inhibitory projection from MPOAEsr1+ cells to ventral tegmental area (VTA) non-dopaminergic cells. Pathway-specific manipulations reveal that this projection is essential for driving pup approach and retrieval and that VTA dopaminergic cells are reliably activated during those behaviors. Altogether, this study provides new insight into the neural circuit that generates maternal behaviors.

Funding information:
  • NIAID NIH HHS - R01 AI046706(United States)
  • NICHD NIH HHS - R21 HD090563()
  • NIMH NIH HHS - R01 MH101377()
  • NIMH NIH HHS - R21 MH105774()
  • NINDS NIH HHS - DP2 NS105553()
  • NINDS NIH HHS - R00 NS087098()

Genetic disruption of fractalkine signaling leads to enhanced loss of cochlear afferents following ototoxic or acoustic injury.

  • Kaur T
  • J. Comp. Neurol.
  • 2018 Apr 1

Literature context: 1122, Life technologies, 1:500, RRID:AB_221569). Cytotoxic cytokine IL-1β was


Abstract:

Cochlear hair cells are vulnerable to a variety of insults like acoustic trauma and ototoxic drugs. Such injury can also lead to degeneration of spiral ganglion neurons (SGNs), but this occurs over a period of months to years. Neuronal survival is necessary for the proper function of cochlear prosthetics, therefore, it is of great interest to understand the mechanisms that regulate neuronal survival in deaf ears. We have recently demonstrated that selective hair cell ablation is sufficient to attract leukocytes into the spiral ganglion, and that fractalkine signaling plays a role in macrophage recruitment and in the survival of auditory neurons. Fractalkine (CX3 CL1), a chemokine that regulates adhesion and migration of leukocytes is expressed by SGNs and signals to leukocytes via its receptor CX3 CR1. The present study has extended the previous findings to more clinically relevant conditions of sensorineural hearing loss by examining the role of fractalkine signaling after aminoglycoside ototoxicity or acoustic trauma. Both aminoglycoside treatment and acoustic overstimulation led to the loss of hair cells as well as prolonged increase in the numbers of cochlear leukocytes. Lack of CX3 CR1 did not affect macrophage recruitment after injury, but resulted in increased loss of SGNs and enhanced expression of the inflammatory cytokine interleukin-1β, when compared to mice with intact CX3 CR1. These data indicate that the dysregulation of macrophage response caused by the absence of CX3 CR1 may contribute to inflammation-mediated neuronal loss in the deafened ear, suggesting a key role for inflammation in the long-term survival of target-deprived afferent neurons.

Funding information:
  • FDA HHS - BB/I004823/1(United States)
  • NIDCD NIH HHS - R01 DC006283()
  • NIDCD NIH HHS - R03 DC015320()

Nav1.1-Overexpressing Interneuron Transplants Restore Brain Rhythms and Cognition in a Mouse Model of Alzheimer's Disease.

  • Martinez-Losa M
  • Neuron
  • 2018 Apr 4

Literature context: cientific Cat# A-11122, RRID:AB_221569 Rabbit anti-Nav1.1 Alomone labs


Abstract:

Inhibitory interneurons regulate the oscillatory rhythms and network synchrony that are required for cognitive functions and disrupted in Alzheimer's disease (AD). Network dysrhythmias in AD and multiple neuropsychiatric disorders are associated with hypofunction of Nav1.1, a voltage-gated sodium channel subunit predominantly expressed in interneurons. We show that Nav1.1-overexpressing, but not wild-type, interneuron transplants derived from the embryonic medial ganglionic eminence (MGE) enhance behavior-dependent gamma oscillatory activity, reduce network hypersynchrony, and improve cognitive functions in human amyloid precursor protein (hAPP)-transgenic mice, which simulate key aspects of AD. Increased Nav1.1 levels accelerated action potential kinetics of transplanted fast-spiking and non-fast-spiking interneurons. Nav1.1-deficient interneuron transplants were sufficient to cause behavioral abnormalities in wild-type mice. We conclude that the efficacy of interneuron transplantation and the function of transplanted cells in an AD-relevant context depend on their Nav1.1 levels. Disease-specific molecular optimization of cell transplants may be required to ensure therapeutic benefits in different conditions.

Funding information:
  • NCRR NIH HHS - C06 RR018928()
  • NIA NIH HHS - F32 AG043301()
  • NIA NIH HHS - R01 AG030207()
  • NIA NIH HHS - R01 AG036884()
  • NIA NIH HHS - R01 AG047313()
  • NIA NIH HHS - R01 AG051390()
  • NIA NIH HHS - R01 AG054214()
  • NIAID NIH HHS - R01 AI059738-05(United States)
  • NINDS NIH HHS - P30 NS065780()
  • NINDS NIH HHS - R01 NS041787()
  • NINDS NIH HHS - U54 NS100717()

An Optical Neuron-Astrocyte Proximity Assay at Synaptic Distance Scales.

  • Octeau JC
  • Neuron
  • 2018 Apr 4

Literature context: s Cat# A11122; RRID:AB_221569 Mouse anti-NeuN (clone A60) Mil


Abstract:

Astrocytes are complex bushy cells that serve important functions through close contacts between their processes and synapses. However, the spatial interactions and dynamics of astrocyte processes relative to synapses have proven problematic to study in adult living brain tissue. Here, we report a genetically targeted neuron-astrocyte proximity assay (NAPA) to measure astrocyte-synapse spatial interactions within intact brain preparations and at synaptic distance scales. The method exploits resonance energy transfer between extracellularly displayed fluorescent proteins targeted to synapses and astrocyte processes. We validated the method in the striatal microcircuitry following in vivo expression. We determined the proximity of striatal astrocyte processes to distinct neuronal input pathways, to D1 and D2 medium spiny neuron synapses, and we evaluated how astrocyte-to-excitatory synapse proximity changed following cortical afferent stimulation, during ischemia and in a model of Huntington's disease. NAPA provides a simple approach to measure astrocyte-synapse spatial interactions in a variety of experimental scenarios. VIDEO ABSTRACT.

Funding information:
  • NCI NIH HHS - R01 CA104926(United States)

Dunce Phosphodiesterase Acts as a Checkpoint for Drosophila Long-Term Memory in a Pair of Serotonergic Neurons.

  • Scheunemann L
  • Neuron
  • 2018 Apr 18

Literature context: Life Technologies Cat. A11122; RRID:AB_221569 Anti-GFP (“GRASP”, mouse) Sigma


Abstract:

A key function of the brain is to filter essential information and store it in the form of stable, long-term memory (LTM). We demonstrate here that the Dunce (Dnc) phosphodiesterase, an important enzyme that degrades cAMP, acts as a molecular switch that controls LTM formation in Drosophila. We show that, during LTM formation, Dnc is inhibited in the SPN, a pair of newly characterized serotonergic neurons, which stimulates the cAMP/PKA pathway. As a consequence, the SPN activates downstream dopaminergic neurons, opening the gate for LTM formation in the olfactory memory center, the mushroom body. Strikingly, transient inhibition of Dnc in the SPN by RNAi was sufficient to induce LTM formation with a training protocol that normally generates only short-lived memory. Thus, Dnc activity in the SPN acts as a memory checkpoint to guarantee that only the most relevant learned experiences are consolidated into stable memory.

Funding information:
  • NIDDK NIH HHS - U19 DK06234(United States)

Ari-1 Regulates Myonuclear Organization Together with Parkin and Is Associated with Aortic Aneurysms.

  • Tan KL
  • Dev. Cell
  • 2018 Apr 23

Literature context: technologies CAT#A11122; RRID:AB_221569 guinea pig polyclonal anti-Msp-


Abstract:

Nuclei are actively positioned and anchored to the cytoskeleton via the LINC (Linker of Nucleoskeleton and Cytoskeleton) complex. We identified mutations in the Parkin-like E3 ubiquitin ligase Ariadne-1 (Ari-1) that affect the localization and distribution of LINC complex members in Drosophila. ari-1 mutants exhibit nuclear clustering and morphology defects in larval muscles. We show that Ari-1 mono-ubiquitinates the core LINC complex member Koi. Surprisingly, we discovered functional redundancy between Parkin and Ari-1: increasing Parkin expression rescues ari-1 mutant phenotypes and vice versa. We further show that rare variants in the human homolog of ari-1 (ARIH1) are associated with thoracic aortic aneurysms and dissections, conditions resulting from smooth muscle cell (SMC) dysfunction. Human ARIH1 rescues fly ari-1 mutant phenotypes, whereas human variants found in patients fail to do so. In addition, SMCs obtained from patients display aberrant nuclear morphology. Hence, ARIH1 is critical in anchoring myonuclei to the cytoskeleton.

Funding information:
  • Intramural NIH HHS - (United States)

Activation of the Notch Signaling Pathway In Vivo Elicits Changes in CSL Nuclear Dynamics.

  • Gomez-Lamarca MJ
  • Dev. Cell
  • 2018 Mar 12

Literature context: ientific Cat# A-11122; RRID:AB_221569 Mouse anti-NICD Developmental S


Abstract:

A key feature of Notch signaling is that it directs immediate changes in transcription via the DNA-binding factor CSL, switching it from repression to activation. How Notch generates both a sensitive and accurate response-in the absence of any amplification step-remains to be elucidated. To address this question, we developed real-time analysis of CSL dynamics including single-molecule tracking in vivo. In Notch-OFF nuclei, a small proportion of CSL molecules transiently binds DNA, while in Notch-ON conditions CSL recruitment increases dramatically at target loci, where complexes have longer dwell times conferred by the Notch co-activator Mastermind. Surprisingly, recruitment of CSL-related corepressors also increases in Notch-ON conditions, revealing that Notch induces cooperative or "assisted" loading by promoting local increase in chromatin accessibility. Thus, in vivo Notch activity triggers changes in CSL dwell times and chromatin accessibility, which we propose confer sensitivity to small input changes and facilitate timely shut-down.

Funding information:
  • Wellcome Trust - CA084179(United Kingdom)
  • Wellcome Trust - R01 CA178974()

Anatomical and Behavioral Investigation of C1ql3 in the Mouse Suprachiasmatic Nucleus.

  • Chew KS
  • J. Biol. Rhythms
  • 2018 Mar 2

Literature context:


Abstract:

Many biochemical, physiological, and behavioral processes such as glucose metabolism, body temperature, and sleep-wake cycles show regular daily rhythms. These circadian rhythms are adjusted to the environmental light-dark cycle by a central pacemaker located in the suprachiasmatic nucleus (SCN) in order for the processes to occur at appropriate times of day. Here, we investigated the expression and function of a synaptic organizing protein, C1QL3, in the SCN. We found that C1ql3 is robustly expressed in the SCN. C1ql3 knockout mice have a reduced density of excitatory synapses in the SCN. In addition, these mice exhibited less consolidated activity to the active portions of the day and period lengthening following a 15-minute phase-delaying light pulse. These data identify C1QL3 as a signaling molecule that is highly expressed in SCN neurons, where it contributes to the formation and/or maintenance of glutamatergic synapses and plays a role in circadian behaviors, which may include circadian aftereffects.

Funding information:
  • Medical Research Council - G0800914(United Kingdom)
  • NIDA NIH HHS - F32 DA031654(United States)
  • NIDCD NIH HHS - R01 DC007395(United States)
  • NIGMS NIH HHS - R01 GM076430(United States)
  • NIGMS NIH HHS - T32 GM007231(United States)
  • NIMH NIH HHS - P50 MH086403(United States)
  • NIMH NIH HHS - R37 MH052804(United States)

Synapse maintenance and restoration in the retina by NGL2.

  • Soto F
  • Elife
  • 2018 Mar 19

Literature context: anti-GFP (rabbit) ThermoFisher RRID:AB_221569 1:1000 dilution


Abstract:

Synaptic cell adhesion molecules (CAMs) promote synapse formation in the developing nervous system. To what extent they maintain and can restore connections in the mature nervous system is unknown. Furthermore, how synaptic CAMs affect the growth of synapse-bearing neurites is unclear. Here, we use adeno-associated viruses (AAVs) to delete, re-, and overexpress the synaptic CAM NGL2 in individual retinal horizontal cells. When we removed NGL2 from horizontal cells, their axons overgrew and formed fewer synapses, irrespective of whether Ngl2 was deleted during development or in mature circuits. When we re-expressed NGL2 in knockout mice, horizontal cell axon territories and synapse numbers were restored, even if AAVs were injected after phenotypes had developed. Finally, overexpression of NGL2 in wild-type horizontal cells elevated synapse numbers above normal levels. Thus, NGL2 promotes the formation, maintenance, and restoration of synapses in the developing and mature retina, and restricts axon growth throughout life.

Funding information:
  • National Eye Institute - R01EY023341()
  • National Eye Institute - R01EY026978()
  • National Eye Institute - R01EY027411()
  • NCI NIH HHS - CA 110793(United States)

An RNAi screen of Rho signalling networks identifies RhoH as a regulator of Rac1 in prostate cancer cell migration.

  • Tajadura-Ortega V
  • BMC Biol.
  • 2018 Mar 6

Literature context: B_439680) or anti-GFP antibody (RRID:AB_221569) and 4′,6-diamidino-2-phenylind


Abstract:

BACKGROUND: Cell migration is essential for development and tissue repair, but it also contributes to disease. Rho GTPases regulate cell migration, but a comprehensive analysis of how each Rho signalling component affects migration has not been carried out. RESULTS: Through an RNA interference screen, and using a prostate cancer cell line, we find that approximately 25% of Rho network components alter migration. Some genes enhance migration while others decrease basal and/or hepatocyte growth factor-stimulated migration. Surprisingly, we identify RhoH as a screen hit. RhoH expression is normally restricted to haematopoietic cells, but we find it is expressed in multiple epithelial cancer cell lines. High RhoH expression in samples from prostate cancer patients correlates with earlier relapse. RhoH depletion reduces cell speed and persistence and decreases migratory polarity. Rac1 activity normally localizes to the front of migrating cells at areas of dynamic membrane movement, but in RhoH-depleted cells active Rac1 is localised around the whole cell periphery and associated with membrane regions that are not extending or retracting. RhoH interacts with Rac1 and with several p21-activated kinases (PAKs), which are Rac effectors. Similar to RhoH depletion, PAK2 depletion increases cell spread area and reduces cell migration. In addition, RhoH depletion reduces lamellipodium extension induced by PAK2 overexpression. CONCLUSIONS: We describe a novel role for RhoH in prostate cancer cell migration. We propose that RhoH promotes cell migration by coupling Rac1 activity and PAK2 to membrane protrusion. Our results also suggest that RhoH expression levels correlate with prostate cancer progression.

Funding information:
  • Cancer Research UK - C41786/A132()
  • Cancer Research UK - C6220/A8833()
  • Cancer Research UK - C6620/A15961()
  • National Institutes of Health - PO1-GM103723()
  • National Institutes of Health - R01-GM079271()
  • National Institutes of Health - U01-EB018816()
  • NCI NIH HHS - R01 CA133966-04(United States)

Analysis of the distribution of spinal NOP receptors in a chronic pain model using NOP-eGFP knock-in mice.

  • Ozawa A
  • Br. J. Pharmacol.
  • 2018 Mar 28

Literature context: arlsbad, CA, USA, Cat# A-11122, RRID:AB_221569); chicken anti-GFP (1:2500, Abc


Abstract:

BACKGROUND AND PURPOSE: The nociceptin/orphanin FQ opioid peptide (NOP) receptor system plays a significant role in the regulation of pain. This system functions differently in the spinal cord and brain. The mechanism by which the NOP receptor agonists regulate pain transmission in these regions is not clearly understood. Here, we investigate the peripheral and spinal NOP receptor distribution and antinociceptive effects of intrathecal nociceptin/orphanin FQ (N/OFQ) in chronic neuropathic pain. EXPERIMENTAL APPROACH: We used immunohistochemistry to determine changes in NOP receptor distribution triggered by spinal nerve ligation (SNL) using NOP-eGFP knock-in mice. Antinociceptive effects of intrathecal N/OFQ on SNL-mediated allodynia and heat/cold hyperalgesia were assessed in wild-type mice. KEY RESULTS: NOP-eGFP immunoreactivity was decreased by SNL in the spinal laminae I and II outer, regions that mediate noxious heat stimuli. In contrast, immunoreactivity of NOP-eGFP was unchanged in the ventral border of lamina II inner, which is an important region for the development of allodynia. NOP-eGFP expression was also decreased in a large number of primary afferents in the L4 dorsal root ganglion (DRG) of SNL mice. However, SNL mice showed increased sensitivity, compared to sham animals to the effects of i.t administered N/OFQ with respect to mechanical as well as thermal stimuli. CONCLUSIONS AND IMPLICATIONS: Our findings suggest that the spinal NOP receptor system attenuates injury-induced hyperalgesia by direct inhibition of the projection neurons in the spinal cord that send nociceptive signals to the brain and not by inhibiting presynaptic terminals of DRG neurons in the superficial lamina.

Funding information:
  • NIDA NIH HHS - R01 DA023281()
  • Wellcome Trust - 089457/Z/09/Z(United Kingdom)

Elevated TREM2 Gene Dosage Reprograms Microglia Responsivity and Ameliorates Pathological Phenotypes in Alzheimer's Disease Models.

  • Lee CYD
  • Neuron
  • 2018 Mar 7

Literature context: mo Fisher Cat# A-11122; RRID:AB_221569 Chicken polyclonal anti-GFP Mil


Abstract:

Variants of TREM2 are associated with Alzheimer's disease (AD). To study whether increasing TREM2 gene dosage could modify the disease pathogenesis, we developed BAC transgenic mice expressing human TREM2 (BAC-TREM2) in microglia. We found that elevated TREM2 expression reduced amyloid burden in the 5xFAD mouse model. Transcriptomic profiling demonstrated that increasing TREM2 levels conferred a rescuing effect, which includes dampening the expression of multiple disease-associated microglial genes and augmenting downregulated neuronal genes. Interestingly, 5xFAD/BAC-TREM2 mice showed further upregulation of several reactive microglial genes linked to phagocytosis and negative regulation of immune cell activation. Moreover, these mice showed enhanced process ramification and phagocytic marker expression in plaque-associated microglia and reduced neuritic dystrophy. Finally, elevated TREM2 gene dosage led to improved memory performance in AD models. In summary, our study shows that a genomic transgene-driven increase in TREM2 expression reprograms microglia responsivity and ameliorates neuropathological and behavioral deficits in AD mouse models.

Funding information:
  • NCI NIH HHS - CA-71514(United States)
  • NIA NIH HHS - R01 AG021173()
  • NIA NIH HHS - R01 AG038710()
  • NIA NIH HHS - R01 AG044420()
  • NIA NIH HHS - R21 AG048519()
  • NIA NIH HHS - RF1 AG056114()
  • NIA NIH HHS - RF1 AG056130()
  • NIMH NIH HHS - U01 MH106008()
  • NINDS NIH HHS - R01 NS030549()
  • NINDS NIH HHS - R01 NS046673()
  • NINDS NIH HHS - R01 NS074312()
  • NINDS NIH HHS - R01 NS084298()

The Transcriptionally Permissive Chromatin State of Embryonic Stem Cells Is Acutely Tuned to Translational Output.

  • Bulut-Karslioglu A
  • Cell Stem Cell
  • 2018 Mar 1

Literature context: Fisher Scientific Cat# A-11122, RRID:AB_221569 Anti-Topors Santa Cruz Biotechn


Abstract:

A permissive chromatin environment coupled to hypertranscription drives the rapid proliferation of embryonic stem cells (ESCs) and peri-implantation embryos. We carried out a genome-wide screen to systematically dissect the regulation of the euchromatic state of ESCs. The results revealed that cellular growth pathways, most prominently translation, perpetuate the euchromatic state and hypertranscription of ESCs. Acute inhibition of translation rapidly depletes euchromatic marks in mouse ESCs and blastocysts, concurrent with delocalization of RNA polymerase II and reduction in nascent transcription. Translation inhibition promotes rewiring of chromatin accessibility, which decreases at a subset of active developmental enhancers and increases at histone genes and transposable elements. Proteome-scale analyses revealed that several euchromatin regulators are unstable proteins and continuously depend on a high translational output. We propose that this mechanistic interdependence of euchromatin, transcription, and translation sets the pace of proliferation at peri-implantation and may be employed by other stem/progenitor cells.

Funding information:
  • NICHD NIH HHS - F30 HD093116()
  • NIGMS NIH HHS - R01 GM113014()
  • NIGMS NIH HHS - R01 GM123556()
  • NIGMS NIH HHS - R01 GM55040(United States)

Clptm1 Limits Forward Trafficking of GABAA Receptors to Scale Inhibitory Synaptic Strength.

  • Ge Y
  • Neuron
  • 2018 Feb 7

Literature context: trogen Cat#11122; RRID:AB_221569 Mouse monoclonal anti-α-Tubulin


Abstract:

In contrast with numerous studies of glutamate receptor-associated proteins and their involvement in the modulation of excitatory synapses, much less is known about mechanisms controlling postsynaptic GABAA receptor (GABAAR) numbers. Using tandem affinity purification from tagged GABAAR γ2 subunit transgenic mice and proteomic analysis, we isolated several GABAAR-associated proteins, including Cleft lip and palate transmembrane protein 1 (Clptm1). Clptm1 interacted with all GABAAR subunits tested and promoted GABAAR trapping in the endoplasmic reticulum. Overexpression of Clptm1 reduced GABAAR-mediated currents in a recombinant system, in cultured hippocampal neurons, and in brain, with no effect on glycine or AMPA receptor-mediated currents. Conversely, knockdown of Clptm1 increased phasic and tonic inhibitory transmission with no effect on excitatory synaptic transmission. Furthermore, altering the expression level of Clptm1 mimicked activity-induced inhibitory synaptic scaling. Thus, in complement to other GABAAR-associated proteins that promote receptor surface expression, Clptm1 limits GABAAR forward trafficking and regulates inhibitory homeostatic plasticity.

Funding information:
  • NHLBI NIH HHS - P01 HL095491(United States)

Myosin VI-Dependent Actin Cages Encapsulate Parkin-Positive Damaged Mitochondria.

  • Kruppa AJ
  • Dev. Cell
  • 2018 Feb 26

Literature context: ischer Scientific Cat# A-11122; RRID:AB_221569 Rabbit polyclonal to GFP Abcam


Abstract:

Mitochondrial quality control is essential to maintain cellular homeostasis and is achieved by removing damaged, ubiquitinated mitochondria via Parkin-mediated mitophagy. Here, we demonstrate that MYO6 (myosin VI), a unique myosin that moves toward the minus end of actin filaments, forms a complex with Parkin and is selectively recruited to damaged mitochondria via its ubiquitin-binding domain. This myosin motor initiates the assembly of F-actin cages to encapsulate damaged mitochondria by forming a physical barrier that prevents refusion with neighboring populations. Loss of MYO6 results in an accumulation of mitophagosomes and an increase in mitochondrial mass. In addition, we observe downstream mitochondrial dysfunction manifesting as reduced respiratory capacity and decreased ability to rely on oxidative phosphorylation for energy production. Our work uncovers a crucial step in mitochondrial quality control: the formation of MYO6-dependent actin cages that ensure isolation of damaged mitochondria from the network.

Funding information:
  • CIHR - 232519(Canada)

Glucocorticoids Drive Diurnal Oscillations in T Cell Distribution and Responses by Inducing Interleukin-7 Receptor and CXCR4.

  • Shimba A
  • Immunity
  • 2018 Feb 20

Literature context: A-11122; RRID:AB_221569 Anti-rabbit IgG (Poly4064)-DyLi


Abstract:

Glucocorticoids are steroid hormones with strong anti-inflammatory and immunosuppressive effects that are produced in a diurnal fashion. Although glucocorticoids have the potential to induce interleukin-7 receptor (IL-7R) expression in T cells, whether they control T cell homeostasis and responses at physiological concentrations remains unclear. We found that glucocorticoid receptor signaling induces IL-7R expression in mouse T cells by binding to an enhancer of the IL-7Rα locus, with a peak at midnight and a trough at midday. This diurnal induction of IL-7R supported the survival of T cells and their redistribution between lymph nodes, spleen, and blood by controlling expression of the chemokine receptor CXCR4. In mice, T cell accumulation in the spleen at night enhanced immune responses against soluble antigens and systemic bacterial infection. Our results reveal the immunoenhancing role of glucocorticoids in adaptive immunity and provide insight into how immune function is regulated by the diurnal rhythm.

Funding information:
  • NIGMS NIH HHS - R01GM071856(United States)

The WAVE Regulatory Complex and Branched F-Actin Counterbalance Contractile Force to Control Cell Shape and Packing in the Drosophila Eye.

  • Del Signore SJ
  • Dev. Cell
  • 2018 Feb 26

Literature context: hermo Fisher Scientific A11122; RRID:AB_221569 Rabbit polyclonal α-DsRed Clone


Abstract:

Contractile forces eliminate cell contacts in many morphogenetic processes. However, mechanisms that balance contractile forces to promote subtler remodeling remain unknown. To address this gap, we investigated remodeling of Drosophila eye lattice cells (LCs), which preserve cell contacts as they narrow to form the edges of a multicellular hexagonal lattice. We found that during narrowing, LC-LC contacts dynamically constrict and expand. Similar to other systems, actomyosin-based contractile forces promote pulses of constriction. Conversely, we found that WAVE-dependent branched F-actin accumulates at LC-LC contacts during expansion and functions to expand the cell apical area, promote shape changes, and prevent elimination of LC-LC contacts. Finally, we found that small Rho GTPases regulate the balance of contractile and protrusive dynamics. These data suggest a mechanism by which WAVE regulatory complex-based F-actin dynamics antagonize contractile forces to regulate cell shape and tissue topology during remodeling and thus contribute to the robustness and precision of the process.

Funding information:
  • NIAID NIH HHS - R01 AI058279-05(United States)

Evolutionally Conserved Function of Kisspeptin Neuronal System Is Nonreproductive Regulation as Revealed by Nonmammalian Study.

  • Nakajo M
  • Endocrinology
  • 2018 Jan 1

Literature context: 2 Rabbit; polyclonal 1:1000 RRID:AB_221569


Abstract:

The kisspeptin neuronal system, which consists of a neuropeptide kisspeptin and its receptor Gpr54, is considered in mammals a key factor of reproductive regulation, the so-called hypothalamic-pituitary-gonadal (HPG) axis. However, in nonmammalian vertebrates, especially in teleosts, existence of kisspeptin regulation on the HPG axis is still controversial. In this study, we applied multidisciplinary techniques to a teleost fish, medaka, and examined possible kisspeptin regulation on the HPG axis. First, we generated knockout medaka for kisspeptin-related genes and found that they show normal fertility, gonadal maturation, and expression of gonadotropins. Moreover, the firing activity of GnRH1 neurons recorded by the patch clamp technique was not altered by kisspeptin application. Furthermore, in goldfish, in vivo kisspeptin administration did not show any positive effect on HPG axis regulation. However, as kisspeptin genes are completely conserved among vertebrates except birds, we surmised that kisspeptin should have some important nonreproductive functions in vertebrates. Therefore, to discover novel functions of kisspeptin, we generated a gpr54-1:enhanced green fluorescent protein (EGFP) transgenic medaka, whose gpr54-1-expressing cells are specifically labeled by EGFP. Analysis of neuronal projection of gpr54-1:EGFP-expressing neurons showed that these neurons in the ventrolateral preoptic area project to the pituitary and are probably involved in endocrine regulation other than gonadotropin release. Furthermore, combination of deep sequencing, histological, and electrophysiological analyses revealed various novel neural systems that are under control of kisspeptin neurons-that is, those expressing neuropeptide Yb, cholecystokinin, isotocin, vasotocin, and neuropeptide B. Thus, our new strategy to genetically label receptor-expressing neurons gives insights into various kisspeptin-dependent neuronal systems that may be conserved in vertebrates.

Endosomal Rab cycles regulate Parkin-mediated mitophagy.

  • Yamano K
  • Elife
  • 2018 Jan 23

Literature context: RRID:AB_221569 1:1000 (IF)


Abstract:

Damaged mitochondria are selectively eliminated by mitophagy. Parkin and PINK1, gene products mutated in familial Parkinson's disease, play essential roles in mitophagy through ubiquitination of mitochondria. Cargo ubiquitination by E3 ubiquitin ligase Parkin is important to trigger selective autophagy. Although autophagy receptors recruit LC3-labeled autophagic membranes onto damaged mitochondria, how other essential autophagy units such as ATG9A-integrated vesicles are recruited remains unclear. Here, using mammalian cultured cells, we demonstrate that RABGEF1, the upstream factor of the endosomal Rab GTPase cascade, is recruited to damaged mitochondria via ubiquitin binding downstream of Parkin. RABGEF1 directs the downstream Rab proteins, RAB5 and RAB7A, to damaged mitochondria, whose associations are further regulated by mitochondrial Rab-GAPs. Furthermore, depletion of RAB7A inhibited ATG9A vesicle assembly and subsequent encapsulation of the mitochondria by autophagic membranes. These results strongly suggest that endosomal Rab cycles on damaged mitochondria are a crucial regulator of mitophagy through assembling ATG9A vesicles.

Funding information:
  • Japan Science and Technology Agency - JPMJCR13M7(International)
  • Japan Society for the Promotion of Science - 16K15095(International)
  • Japan Society for the Promotion of Science - JP15H01196(International)
  • Japan Society for the Promotion of Science - JP16K18545(International)
  • Japan Society for the Promotion of Science - JP26000014(International)
  • Japan Society for the Promotion of Science - JP26111729(International)
  • Japan Society for the Promotion of Science - JP26840033(International)
  • NIDCR NIH HHS - R03 DE018415-02(United States)
  • NINDS NIH HHS - Intramural program(United States)

An Image-Based miRNA Screen Identifies miRNA-135s As Regulators of CNS Axon Growth and Regeneration by Targeting Krüppel-like Factor 4.

  • van Battum EY
  • J. Neurosci.
  • 2018 Jan 17

Literature context:


Abstract:

During embryonic development, axons extend over long distances to establish functional connections. In contrast, axon regeneration in the adult mammalian CNS is limited in part by a reduced intrinsic capacity for axon growth. Therefore, insight into the intrinsic control of axon growth may provide new avenues for enhancing CNS regeneration. Here, we performed one of the first miRNome-wide functional miRNA screens to identify miRNAs with robust effects on axon growth. High-content screening identified miR-135a and miR-135b as potent stimulators of axon growth and cortical neuron migration in vitro and in vivo in male and female mice. Intriguingly, both of these developmental effects of miR-135s relied in part on silencing of Krüppel-like factor 4 (KLF4), a well known intrinsic inhibitor of axon growth and regeneration. These results prompted us to test the effect of miR-135s on axon regeneration after injury. Our results show that intravitreal application of miR-135s facilitates retinal ganglion cell (RGC) axon regeneration after optic nerve injury in adult mice in part by repressing KLF4. In contrast, depletion of miR-135s further reduced RGC axon regeneration. Together, these data identify a novel neuronal role for miR-135s and the miR-135-KLF4 pathway and highlight the potential of miRNAs as tools for enhancing CNS axon regeneration.SIGNIFICANCE STATEMENT Axon regeneration in the adult mammalian CNS is limited in part by a reduced intrinsic capacity for axon growth. Therefore, insight into the intrinsic control of axon growth may provide new avenues for enhancing regeneration. By performing an miRNome-wide functional screen, our studies identify miR-135s as stimulators of axon growth and neuron migration and show that intravitreal application of these miRNAs facilitates CNS axon regeneration after nerve injury in adult mice. Intriguingly, these developmental and regeneration-promoting effects rely in part on silencing of Krüppel-like factor 4 (KLF4), a well known intrinsic inhibitor of axon regeneration. Our data identify a novel neuronal role for the miR-135-KLF4 pathway and support the idea that miRNAs can be used for enhancing CNS axon regeneration.

Funding information:
  • NCI NIH HHS - R01 CA112054(United States)

Notch Signaling Regulates Differentiation and Steroidogenesis in Female Mouse Ovarian Granulosa Cells.

  • Prasasya RD
  • Endocrinology
  • 2018 Jan 1

Literature context:


Abstract:

The Notch pathway is a highly conserved juxtacrine signaling mechanism that is important for many cellular processes during development, including differentiation and proliferation. Although Notch is important during ovarian follicle formation and early development, its functions during the gonadotropin-dependent stages of follicle development are largely unexplored. We observed positive regulation of Notch activity and expression of Notch ligands and receptors following activation of the luteinizing hormone-receptor in prepubertal mouse ovary. JAG1, the most abundantly expressed Notch ligand in mouse ovary, revealed a striking shift in localization from oocytes to somatic cells following hormone stimulation. Using primary cultures of granulosa cells, we investigated the functions of Jag1 using small interfering RNA knockdown. The loss of JAG1 led to suppression of granulosa cell differentiation as marked by reduced expression of enzymes and factors involved in steroid biosynthesis, and in steroid secretion. Jag1 knockdown also resulted in enhanced cell proliferation. These phenotypes were replicated, although less robustly, following knockdown of the obligate canonical Notch transcription factor RBPJ. Intracellular signaling analysis revealed increased activation of the mitogenic phosphatidylinositol 3-kinase/protein kinase B and mitogen-activated protein kinase/extracellular signal-regulated kinase pathways following Notch knockdown, with a mitogen-activated protein kinase kinase inhibitor blocking the enhanced proliferation observed in Jag1 knockdown granulosa cells. Activation of YB-1, a known regulator of granulosa cell differentiation genes, was suppressed by Jag1 knockdown. Overall, this study reveals a role of Notch signaling in promoting the differentiation of preovulatory granulosa cells, adding to the diverse functions of Notch in the mammalian ovary.

Funding information:
  • NIA NIH HHS - R56 AG016379(United States)
  • NICHD NIH HHS - P01 HD021921(United States)
  • NICHD NIH HHS - P50 HD028934(United States)
  • NIGMS NIH HHS - T32 GM008061(United States)

Sonic Hedgehog Is a Remotely Produced Cue that Controls Axon Guidance Trans-axonally at a Midline Choice Point.

  • Peng J
  • Neuron
  • 2018 Jan 17

Literature context: Fisher Scientific Cat# A-11122; RRID:AB_221569 Rat monoclonal anti-mCherry The


Abstract:

At the optic chiasm choice point, ipsilateral retinal ganglion cells (RGCs) are repelled away from the midline by guidance cues, including Ephrin-B2 and Sonic Hedgehog (Shh). Although guidance cues are normally produced by cells residing at the choice point, the mRNA for Shh is not found at the optic chiasm. Here we show that Shh protein is instead produced by contralateral RGCs at the retina, transported anterogradely along the axon, and accumulates at the optic chiasm to repel ipsilateral RGCs. In vitro, contralateral RGC axons, which secrete Shh, repel ipsilateral RGCs in a Boc- and Smo-dependent manner. Finally, knockdown of Shh in the contralateral retina causes a decrease in the proportion of ipsilateral RGCs in a non-cell-autonomous manner. These findings reveal a role for axon-axon interactions in ipsilateral RGC guidance, and they establish that remotely produced cues can act at axon guidance midline choice points.

Caveolin1 Identifies a Specific Subpopulation of Cerebral Cortex Callosal Projection Neurons (CPN) Including Dual Projecting Cortical Callosal/Frontal Projection Neurons (CPN/FPN).

  • MacDonald JL
  • eNeuro
  • 2018 Jan 31

Literature context: , 1:500 (Invitrogen; RRID:AB_221569); mouse anti-SATB2, 1:500 (Abca


Abstract:

The neocortex is composed of many distinct subtypes of neurons that must form precise subtype-specific connections to enable the cortex to perform complex functions. Callosal projection neurons (CPN) are the broad population of commissural neurons that connect the cerebral hemispheres via the corpus callosum (CC). Currently, how the remarkable diversity of CPN subtypes and connectivity is specified, and how they differentiate to form highly precise and specific circuits, are largely unknown. We identify in mouse that the lipid-bound scaffolding domain protein Caveolin 1 (CAV1) is specifically expressed by a unique subpopulation of Layer V CPN that maintain dual ipsilateral frontal projections to premotor cortex. CAV1 is expressed by over 80% of these dual projecting callosal/frontal projection neurons (CPN/FPN), with expression peaking early postnatally as axonal and dendritic targets are being reached and refined. CAV1 is localized to the soma and dendrites of CPN/FPN, a unique population of neurons that shares information both between hemispheres and with premotor cortex, suggesting function during postmitotic development and refinement of these neurons, rather than in their specification. Consistent with this, we find that Cav1 function is not necessary for the early specification of CPN/FPN, or for projecting to their dual axonal targets. CPN subtype-specific expression of Cav1 identifies and characterizes a first molecular component that distinguishes this functionally unique projection neuron population, a population that expands in primates, and is prototypical of additional dual and higher-order projection neuron subtypes.

Funding information:
  • NIGMS NIH HHS - GM007757(United States)

A Genetically Defined Circuit for Arousal from Sleep during Hypercapnia.

  • Kaur S
  • Neuron
  • 2017 Dec 6

Literature context: oFisher Scientific Cat# A11122, RRID:AB_10073917 Rabbit anti-dsRed, Clontech Cat


Abstract:

The precise neural circuitry that mediates arousal during sleep apnea is not known. We previously found that glutamatergic neurons in the external lateral parabrachial nucleus (PBel) play a critical role in arousal to elevated CO2 or hypoxia. Because many of the PBel neurons that respond to CO2 express calcitonin gene-related peptide (CGRP), we hypothesized that CGRP may provide a molecular identifier of the CO2 arousal circuit. Here, we report that selective chemogenetic and optogenetic activation of PBelCGRP neurons caused wakefulness, whereas optogenetic inhibition of PBelCGRP neurons prevented arousal to CO2, but not to an acoustic tone or shaking. Optogenetic inhibition of PBelCGRP terminals identified a network of forebrain sites under the control of a PBelCGRP switch that is necessary to arouse animals from hypercapnia. Our findings define a novel cellular target for interventions that may prevent sleep fragmentation and the attendant cardiovascular and cognitive consequences seen in obstructive sleep apnea. VIDEO ABSTRACT.

Funding information:
  • NHLBI NIH HHS - P01 HL095491()
  • NINDS NIH HHS - R01 NS085477()

Hippocampal oxytocin receptors are necessary for discrimination of social stimuli.

  • Raam T
  • Nat Commun
  • 2017 Dec 8

Literature context: 1 : 500, Antibodyregistry.org: RRID:AB_221569); goat anti-GFP, Novus Biologic


Abstract:

Oxytocin receptor (Oxtr) signaling in neural circuits mediating discrimination of social stimuli and affiliation or avoidance behavior is thought to guide social recognition. Remarkably, the physiological functions of Oxtrs in the hippocampus are not known. Here we demonstrate using genetic and pharmacological approaches that Oxtrs in the anterior dentate gyrus (aDG) and anterior CA2/CA3 (aCA2/CA3) of mice are necessary for discrimination of social, but not non-social, stimuli. Further, Oxtrs in aCA2/CA3 neurons recruit a population-based coding mechanism to mediate social stimuli discrimination. Optogenetic terminal-specific attenuation revealed a critical role for aCA2/CA3 outputs to posterior CA1 for discrimination of social stimuli. In contrast, aCA2/CA3 projections to aCA1 mediate discrimination of non-social stimuli. These studies identify a role for an aDG-CA2/CA3 axis of Oxtr expressing cells in discrimination of social stimuli and delineate a pathway relaying social memory computations in the anterior hippocampus to the posterior hippocampus to guide social recognition.

Funding information:
  • NIA NIH HHS - RF1 AG048908()
  • NIAAA NIH HHS - R01 AA014405(United States)
  • NIMH NIH HHS - R01 MH104175()
  • NIMH NIH HHS - R01 MH111729()

Mechanosensory-Based Phase Coding of Odor Identity in the Olfactory Bulb.

  • Iwata R
  • Neuron
  • 2017 Dec 6

Literature context: at# A11122; RRID:AB_221569 Chicken anti-GFP Aves Labs Cat#


Abstract:

Mitral and tufted (M/T) cells in the olfactory bulb produce rich temporal patterns of activity in response to different odors. However, it remains unknown how these temporal patterns are generated and how they are utilized in olfaction. Here we show that temporal patterning effectively discriminates between the two sensory modalities detected by olfactory sensory neurons (OSNs): odor and airflow-driven mechanical signals. Sniff-induced mechanosensation generates glomerulus-specific oscillatory activity in M/T cells, whose phase was invariant across airflow speed. In contrast, odor stimulation caused phase shifts (phase coding). We also found that odor-evoked phase shifts are concentration invariant and stable across multiple sniff cycles, contrary to the labile nature of rate coding. The loss of oscillatory mechanosensation impaired the precision and stability of phase coding, demonstrating its role in olfaction. We propose that phase, not rate, coding is a robust encoding strategy of odor identity and is ensured by airflow-induced mechanosensation in OSNs.

Funding information:
  • Wellcome Trust - G0401641(United Kingdom)

Dendritic and Axonal L-Type Calcium Channels Cooperate to Enhance Motoneuron Firing Output during Drosophila Larval Locomotion.

  • Kadas D
  • J. Neurosci.
  • 2017 Nov 8

Literature context: GFP, 1:400, Invitrogen, A11122, RRID:AB_221569; mouse anti-Brp, nc82, DSHB, 1:


Abstract:

Behaviorally adequate neuronal firing patterns are critically dependent on the specific types of ion channel expressed and on their subcellular localization. This study combines in situ electrophysiology with genetic and pharmacological intervention in larval Drosophila melanogaster of both sexes to address localization and function of L-type like calcium channels in motoneurons. We demonstrate that Dmca1D (Cav1 homolog) L-type like calcium channels localize to both the somatodendritic and the axonal compartment of larval crawling motoneurons. In situ patch-clamp recordings in genetic mosaics reveal that Dmca1D channels increase burst duration and maximum intraburst firing frequencies during crawling-like motor patterns in semi-intact animals. Genetic and acute pharmacological manipulations suggest that prolonged burst durations are caused by dendritically localized Dmca1D channels, which activate upon cholinergic synaptic input and amplify EPSPs, thus indicating a conserved function of dendritic L-type channels from Drosophila to vertebrates. By contrast, maximum intraburst firing rates require axonal calcium influx through Dmca1D channels, likely to enhance sodium channel de-inactivation via a fast afterhyperpolarization through BK channel activation. Therefore, in unmyelinated Drosophila motoneurons different functions of axonal and dendritic L-type like calcium channels likely operate synergistically to maximize firing output during locomotion.SIGNIFICANCE STATEMENT Nervous system function depends on the specific excitabilities of different types of neurons. Excitability is largely shaped by different combinations of voltage-dependent ion channels. Despite a high degree of conservation, the huge diversity of ion channel types and their differential localization pose challenges in assigning distinct functions to specific channels across species. We find a conserved role, from fruit flies to mammals, for L-type calcium channels in augmenting motoneuron excitability. As in spinal cord, dendritic L-type channels amplify excitatory synaptic input. In contrast to spinal motoneurons, axonal L-type channels enhance firing rates in unmyelinated Drosophila motoraxons. Therefore, enhancing motoneuron excitability by L-type channels seems an old strategy, but localization and interactions with other channels are tuned to species-specific requirements.

Funding information:
  • NIAAA NIH HHS - R01 AA012223(United States)

An αII Spectrin-Based Cytoskeleton Protects Large-Diameter Myelinated Axons from Degeneration.

  • Huang CY
  • J. Neurosci.
  • 2017 Nov 22

Literature context: cientific; RRID:AB_221569), ATF3 (Santa Cruz Biotechnolog


Abstract:

Axons must withstand mechanical forces, including tension, torsion, and compression. Spectrins and actin form a periodic cytoskeleton proposed to protect axons against these forces. However, because spectrins also participate in assembly of axon initial segments (AISs) and nodes of Ranvier, it is difficult to uncouple their roles in maintaining axon integrity from their functions at AIS and nodes. To overcome this problem and to determine the importance of spectrin cytoskeletons for axon integrity, we generated mice with αII spectrin-deficient peripheral sensory neurons. The axons of these neurons are very long and exposed to the mechanical forces associated with limb movement; most lack an AIS, and some are unmyelinated and have no nodes. We analyzed αII spectrin-deficient mice of both sexes and found that, in myelinated axons, αII spectrin forms a periodic cytoskeleton with βIV and βII spectrin at nodes of Ranvier and paranodes, respectively, but that loss of αII spectrin disrupts this organization. Avil-cre;Sptan1f/f mice have reduced numbers of nodes, disrupted paranodal junctions, and mislocalized Kv1 K+ channels. We show that the density of nodal βIV spectrin is constant among axons, but the density of nodal αII spectrin increases with axon diameter. Remarkably, Avil-cre;Sptan1f/f mice have intact nociception and small-diameter axons, but severe ataxia due to preferential degeneration of large-diameter myelinated axons. Our results suggest that nodal αII spectrin helps resist the mechanical forces experienced by large-diameter axons, and that αII spectrin-dependent cytoskeletons are also required for assembly of nodes of Ranvier.SIGNIFICANCE STATEMENT A periodic axonal cytoskeleton consisting of actin and spectrin has been proposed to help axons resist the mechanical forces to which they are exposed (e.g., compression, torsion, and stretch). However, until now, no vertebrate animal model has tested the requirement of the spectrin cytoskeleton in maintenance of axon integrity. We demonstrate the role of the periodic spectrin-dependent cytoskeleton in axons and show that loss of αII spectrin from PNS axons causes preferential degeneration of large-diameter myelinated axons. We show that nodal αII spectrin is found at greater densities in large-diameter myelinated axons, suggesting that nodes are particularly vulnerable domains requiring a specialized cytoskeleton to protect against axon degeneration.

αII Spectrin Forms a Periodic Cytoskeleton at the Axon Initial Segment and Is Required for Nervous System Function.

  • Huang CY
  • J. Neurosci.
  • 2017 Nov 22

Literature context:


Abstract:

Spectrins form a submembranous cytoskeleton proposed to confer strength and flexibility to neurons and to participate in ion channel clustering at axon initial segments (AIS) and nodes of Ranvier. Neuronal spectrin cytoskeletons consist of diverse β subunits and αII spectrin. Although αII spectrin is found in neurons in both axonal and somatodendritic domains, using proteomics, biochemistry, and superresolution microscopy, we show that αII and βIV spectrin interact and form a periodic AIS cytoskeleton. To determine the role of spectrins in the nervous system, we generated Sptan1f/f mice for deletion of CNS αII spectrin. We analyzed αII spectrin-deficient mice of both sexes and found that loss of αII spectrin causes profound reductions in all β spectrins. αII spectrin-deficient mice die before 1 month of age and have disrupted AIS and many other neurological impairments including seizures, disrupted cortical lamination, and widespread neurodegeneration. These results demonstrate the importance of the spectrin cytoskeleton both at the AIS and throughout the nervous system.SIGNIFICANCE STATEMENT Spectrin cytoskeletons play diverse roles in neurons, including assembly of excitable domains such as the axon initial segment (AIS) and nodes of Ranvier. However, the molecular composition and structure of these cytoskeletons remain poorly understood. Here, we show that αII spectrin partners with βIV spectrin to form a periodic cytoskeleton at the AIS. Using a new αII spectrin conditional knock-out mouse, we show that αII spectrin is required for AIS assembly, neuronal excitability, cortical lamination, and to protect against neurodegeneration. These results demonstrate the broad importance of spectrin cytoskeletons for nervous system function and development and have important implications for nervous system injuries and diseases because disruption of the spectrin cytoskeleton is a common molecular pathology.

CaMKIIα Expression Defines Two Functionally Distinct Populations of Granule Cells Involved in Different Types of Odor Behavior.

  • Malvaut S
  • Curr. Biol.
  • 2017 Nov 6

Literature context: Fisher Scientific Cat# A-11122; RRID:AB_221569 Chicken polyclonal anti-GFP Avé


Abstract:

Granule cells (GCs) in the olfactory bulb (OB) play an important role in odor information processing. Although they have been classified into various neurochemical subtypes, the functional roles of these subtypes remain unknown. We used in vivo two-photon Ca2+ imaging combined with cell-type-specific identification of GCs in the mouse OB to examine whether functionally distinct GC subtypes exist in the bulbar network. We showed that half of GCs express Ca2+/calmodulin-dependent protein kinase IIα (CaMKIIα+) and that these neurons are preferentially activated by olfactory stimulation. The higher activity of CaMKIIα+ neurons is due to the weaker inhibitory input that they receive compared to their CaMKIIα-immunonegative (CaMKIIα-) counterparts. In line with these functional data, immunohistochemical analyses showed that 75%-90% of GCs expressing the immediate early gene cFos are CaMKIIα+ in naive animals and in mice that have been exposed to a novel odor and go/no-go operant conditioning, or that have been subjected to long-term associative memory and spontaneous habituation/dishabituation odor discrimination tasks. On the other hand, a perceptual learning task resulted in increased activation of CaMKIIα- cells. Pharmacogenetic inhibition of CaMKIIα+ GCs revealed that this subtype is involved in habituation/dishabituation and go/no-go odor discrimination, but not in perceptual learning. In contrast, pharmacogenetic inhibition of GCs in a subtype-independent manner affected perceptual learning. Our results indicate that functionally distinct populations of GCs exist in the OB and that they play distinct roles during different odor tasks.

Funding information:
  • NIAMS NIH HHS - R21-AR-063846(United States)

Transsynaptic Mapping of Second-Order Taste Neurons in Flies by trans-Tango.

  • Talay M
  • Neuron
  • 2017 Nov 15

Literature context: Fisher Scientific Cat# A11122; RRID:AB_221569 anti-HA (mouse monoclonal) Cova


Abstract:

Mapping neural circuits across defined synapses is essential for understanding brain function. Here we describe trans-Tango, a technique for anterograde transsynaptic circuit tracing and manipulation. At the core of trans-Tango is a synthetic signaling pathway that is introduced into all neurons in the animal. This pathway converts receptor activation at the cell surface into reporter expression through site-specific proteolysis. Specific labeling is achieved by presenting a tethered ligand at the synapses of genetically defined neurons, thereby activating the pathway in their postsynaptic partners and providing genetic access to these neurons. We first validated trans-Tango in the Drosophila olfactory system and then implemented it in the gustatory system, where projections beyond the first-order receptor neurons are not fully characterized. We identified putative second-order neurons within the sweet circuit that include projection neurons targeting known neuromodulation centers in the brain. These experiments establish trans-Tango as a flexible platform for transsynaptic circuit analysis.

Funding information:
  • NIDCD NIH HHS - R01 DC013561()
  • NIDCD NIH HHS - R21 DC014333()
  • NIMH NIH HHS - R01 MH086920()
  • NIMH NIH HHS - R01 MH105368()

Vg1-Nodal heterodimers are the endogenous inducers of mesendoderm.

  • Montague TG
  • Elife
  • 2017 Nov 15

Literature context: anti-GFP, ThermoFisher A11122, RRID:AB_221569; 1:2000 rabbit anti-Flag, Sigma


Abstract:

Nodal is considered the key inducer of mesendoderm in vertebrate embryos and embryonic stem cells. Other TGF-beta-related signals, such as Vg1/Dvr1/Gdf3, have also been implicated in this process but their roles have been unclear or controversial. Here we report that zebrafish embryos without maternally provided vg1 fail to form endoderm and head and trunk mesoderm, and closely resemble nodal loss-of-function mutants. Although Nodal is processed and secreted without Vg1, it requires Vg1 for its endogenous activity. Conversely, Vg1 is unprocessed and resides in the endoplasmic reticulum without Nodal, and is only secreted, processed and active in the presence of Nodal. Co-expression of Nodal and Vg1 results in heterodimer formation and mesendoderm induction. Thus, mesendoderm induction relies on the combination of two TGF-beta-related signals: maternal and ubiquitous Vg1, and zygotic and localized Nodal. Modeling reveals that the pool of maternal Vg1 enables rapid signaling at low concentrations of zygotic Nodal.

Parkinson's Disease-Associated LRRK2 Hyperactive Kinase Mutant Disrupts Synaptic Vesicle Trafficking in Ventral Midbrain Neurons.

  • Pan PY
  • J. Neurosci.
  • 2017 Nov 22

Literature context: ic catalog #A-11122 also A11122 RRID:AB_221569) overnight, followed by 1 h inc


Abstract:

Parkinson's disease (PD) is characterized pathologically by the selective loss of substantia nigra (SN) dopaminergic (DAergic) neurons. Recent evidence has suggested a role of LRRK2, linked to the most frequent familial PD, in regulating synaptic vesicle (SV) trafficking. However, the mechanism whereby LRRK2 mutants contribute to nigral vulnerability remains unclear. Here we show that the most common PD mutation LRRK2 G2019S impairs SV endocytosis in ventral midbrain (MB) neurons, including DA neurons, and the slowed endocytosis can be rescued by inhibition of LRRK2 kinase activity. A similar endocytic defect, however, was not observed in LRRK2 mutant neurons from the neocortex (hereafter, cortical neurons) or the hippocampus, suggesting a brain region-specific vulnerability to the G2019S mutation. Additionally, we found MB-specific impairment of SV endocytosis in neurons carrying heterozygous deletion of SYNJ1 (PARK20), a gene that is associated with recessive Parkinsonism. Combining SYNJ1+/- and LRRK2 G2019S does not exacerbate SV endocytosis but impairs sustained exocytosis in MB neurons and alters specific motor functions of 1-year-old male mice. Interestingly, we show that LRRK2 directly phosphorylates synaptojanin1 in vitro, resulting in the disruption of endophilin-synaptojanin1 interaction required for SV endocytosis. Our work suggests a merge of LRRK2 and SYNJ1 pathogenic pathways in deregulating SV trafficking in MB neurons as an underlying molecular mechanism of early PD pathogenesis.SIGNIFICANCE STATEMENT Understanding midbrain dopaminergic (DAergic) neuron-selective vulnerability in PD is essential for the development of targeted therapeutics. We report, for the first time, a nerve terminal impairment in SV trafficking selectively in MB neurons but not cortical neurons caused by two PARK genes: LRRK2 (PARK8) and SYNJ1 (PARK20). We demonstrate that the enhanced kinase activity resulting from the most frequent G2019S mutation in LRRK2 is the key to this impairment. We provide evidence suggesting that LRRK2 G2019S and SYNJ1 loss of function share a similar pathogenic pathway in deregulating DAergic neuron SV endocytosis and that they play additive roles in facilitating each other's pathogenic functions in PD.

A versatile genetic tool for post-translational control of gene expression in Drosophila melanogaster.

  • Sethi S
  • Elife
  • 2017 Nov 15

Literature context: RRID:AB_221569 1:200


Abstract:

Several techniques have been developed to manipulate gene expression temporally in intact neural circuits. However, the applicability of current tools developed for in vivo studies in Drosophila is limited by their incompatibility with existing GAL4 lines and side effects on physiology and behavior. To circumvent these limitations, we adopted a strategy to reversibly regulate protein degradation with a small molecule by using a destabilizing domain (DD). We show that this system is effective across different tissues and developmental stages. We further show that this system can be used to control in vivo gene expression levels with low background, large dynamic range, and in a reversible manner without detectable side effects on the lifespan or behavior of the animal. Additionally, we engineered tools for chemically controlling gene expression (GAL80-DD) and recombination (FLP-DD). We demonstrate the applicability of this technology in manipulating neuronal activity and for high-efficiency sparse labeling of neuronal populations.

Sparse genetic tracing reveals regionally specific functional organization of mammalian nociceptors.

  • Olson W
  • Elife
  • 2017 Oct 12

Literature context: , MA, Cat# A-11122 also A11122, RRID:AB_221569), conjugated IB4-Alex488 (Molec


Abstract:

The human distal limbs have a high spatial acuity for noxious stimuli but a low density of pain-sensing neurites. To elucidate mechanisms underlying regional differences in processing nociception, we sparsely traced non-peptidergic nociceptors across the body using a newly generated MrgprdCreERT2 mouse line. We found that mouse plantar paw skin is also innervated by a low density of Mrgprd+ nociceptors, while individual arbors in different locations are comparable in size. Surprisingly, the central arbors of plantar paw and trunk innervating nociceptors have distinct morphologies in the spinal cord. This regional difference is well correlated with a heightened signal transmission for plantar paw circuits, as revealed by both spinal cord slice recordings and behavior assays. Taken together, our results elucidate a novel somatotopic functional organization of the mammalian pain system and suggest that regional central arbor structure could facilitate the "enlarged representation" of plantar paw regions in the CNS.

Funding information:
  • NIGMS NIH HHS - K12 GM081259()
  • NINDS NIH HHS - F31 NS092297()
  • NINDS NIH HHS - R01 NS083702()
  • NINDS NIH HHS - R01 NS094224()

Channel Nucleoporins Recruit PLK-1 to Nuclear Pore Complexes to Direct Nuclear Envelope Breakdown in C. elegans.

  • Martino L
  • Dev. Cell
  • 2017 Oct 23

Literature context: i-GFP ThermoFisher Cat#A-11122; RRID:AB_221569 StrepTactin-HRP IBA Cat#2-1502-


Abstract:

In animal cells, nuclear envelope breakdown (NEBD) is required for proper chromosome segregation. Whereas mitotic kinases have been implicated in NEBD, how they coordinate their activity to trigger this event is unclear. Here, we show that both in human cells and Caenorhabditis elegans, the Polo-like kinase 1 (PLK-1) is recruited to the nuclear pore complexes, just prior to NEBD, through its Polo-box domain (PBD). We provide evidence that PLK-1 localization to the nuclear envelope (NE) is required for efficient NEBD. We identify the central channel nucleoporins NPP-1/Nup58, NPP-4/Nup54, and NPP-11/Nup62 as the critical factors anchoring PLK-1 to the NE in C. elegans. In particular, NPP-1, NPP-4, and NPP-11 primed at multiple Polo-docking sites by Cdk1 and PLK-1 itself physically interact with the PLK-1 PBD. We conclude that nucleoporins play an unanticipated regulatory role in NEBD, by recruiting PLK-1 to the NE thereby facilitating phosphorylation of critical downstream targets.

Vesicular Glutamate Transporter 1 Knockdown in Infralimbic Prefrontal Cortex Augments Neuroendocrine Responses to Chronic Stress in Male Rats.

  • Myers B
  • Endocrinology
  • 2017 Oct 1

Literature context: 22 Rabbit; polyclonal 1:1000 RRID:AB_221569


Abstract:

Chronic stress-associated pathologies frequently associate with alterations in the structure and activity of the medial prefrontal cortex (mPFC). However, the influence of infralimbic cortex (IL) projection neurons on hypothalamic-pituitary-adrenal (HPA) axis activity is unknown, as is the involvement of these cells in chronic stress-induced endocrine alterations. In the current study, a lentiviral-packaged vector coding for a small interfering RNA (siRNA) targeting vesicular glutamate transporter (vGluT) 1 messenger RNA (mRNA) was microinjected into the IL of male rats. vGluT1 is responsible for presynaptic vesicular glutamate packaging in cortical neurons, and knockdown reduces the amount of glutamate available for synaptic release. After injection, rats were either exposed to chronic variable stress (CVS) or remained in the home cage as unstressed controls. Fifteen days after the initiation of CVS, all animals were exposed to a novel acute stressor (30-minute restraint) with blood collection for the analysis of adrenocorticotropic hormone (ACTH) and corticosterone. Additionally, brains were collected for in situ hybridization of corticotrophin-releasing hormone mRNA. In previously unstressed rats, vGluT1 siRNA significantly enhanced ACTH and corticosterone secretion. Compared with CVS animals receiving the green fluorescent protein control vector, the vGluT1 siRNA further increased basal and stress-induced corticosterone release. Further analysis revealed enhanced adrenal responsiveness in CVS rats treated with vGluT1 siRNA. Collectively, our results suggest that IL glutamate output inhibits HPA responses to acute stress and restrains corticosterone secretion during chronic stress, possibly at the level of the adrenal. Together, these findings pinpoint a neurochemical mechanism linking mPFC dysfunction with aberrant neuroendocrine responses to chronic stress.

Microenvironment-Driven Shift of Cohesion/Detachment Balance within Tumors Induces a Switch toward Metastasis in Neuroblastoma.

  • Delloye-Bourgeois C
  • Cancer Cell
  • 2017 Oct 9

Literature context: Fisher Scientific Cat# A-11122; RRID:AB_221569 anti-SMA : Mouse Anti-Actin, al


Abstract:

Neuroblastoma (NB) is a childhood cancer arising from sympatho-adrenal neural crest cells. Disseminated forms have high frequency of multiple tumoral foci whose etiology remains unknown; NB embryonic origin limits investigations in patients and current models. We developed an avian embryonic model driving human NB tumorigenesis in tissues homologous to patients. We found that aggressive NBs display a metastatic mode, secondary dissemination via peripheral nerves and aorta. Through tumor transcriptional profiling, we found that NB dissemination is induced by the shutdown of a pro-cohesion autocrine signal, SEMA3C, which constrains the tumoral mass. Lowering SEMA3C levels shifts the balance toward detachment, triggering NB cells to collectively evade the tumor. Together with patient cohort analysis, this identifies a microenvironment-driven pro-metastatic switch for NB.

Adaptive Evolution Leads to Cross-Species Incompatibility in the piRNA Transposon Silencing Machinery.

  • Parhad SS
  • Dev. Cell
  • 2017 Oct 9

Literature context: sher Scientific Cat# A11122, RRID:AB_221569 Chemicals, Peptides, and Recomb


Abstract:

Reproductive isolation defines species divergence and is linked to adaptive evolution of hybrid incompatibility genes. Hybrids between Drosophila melanogaster and Drosophila simulans are sterile, and phenocopy mutations in the PIWI interacting RNA (piRNA) pathway, which silences transposons and shows pervasive adaptive evolution, and Drosophila rhino and deadlock encode rapidly evolving components of a complex that binds to piRNA clusters. We show that Rhino and Deadlock interact and co-localize in simulans and melanogaster, but simulans Rhino does not bind melanogaster Deadlock, due to substitutions in the rapidly evolving Shadow domain. Significantly, a chimera expressing the simulans Shadow domain in a melanogaster Rhino backbone fails to support piRNA production, disrupts binding to piRNA clusters, and leads to ectopic localization to bulk heterochromatin. Fusing melanogaster Deadlock to simulans Rhino, by contrast, restores localization to clusters. Deadlock binding thus directs Rhino to piRNA clusters, and Rhino-Deadlock co-evolution has produced cross-species incompatibilities, which may contribute to reproductive isolation.

Funding information:
  • NICHD NIH HHS - P01 HD078253()
  • NICHD NIH HHS - R01 HD049116()

Steroid Hormone Ecdysone Signaling Specifies Mushroom Body Neuron Sequential Fate via Chinmo.

  • Marchetti G
  • Curr. Biol.
  • 2017 Oct 9

Literature context: s Cat# A11122; RRID:AB_221569 rabbit anti-β-gal (Cappel) MP B


Abstract:

The functional variety in neuronal composition of an adult brain is established during development. Recent studies proposed that interactions between genetic intrinsic programs and external cues are necessary to generate proper neural diversity [1]. However, the molecular mechanisms underlying this developmental process are still poorly understood. Three main subtypes of Drosophila mushroom body (MB) neurons are sequentially generated during development and provide a good example of developmental neural plasticity [2]. Our present data propose that the environmentally controlled steroid hormone ecdysone functions as a regulator of early-born MB neuron fate during larval-pupal transition. We found that the BTB-zinc finger factor Chinmo acts upstream of ecdysone signaling to promote a neuronal fate switch. Indeed, Chinmo regulates the expression of the ecdysone receptor B1 isoform to mediate the production of γ and α'β' MB neurons. In addition, we provide genetic evidence for a regulatory negative feedback loop driving the α'β' to αβ MB neuron transition in which ecdysone signaling in turn controls microRNA let-7 depression of Chinmo expression. Thus, our results uncover a novel interaction in the MB neural specification pathway for temporal control of neuronal identity by interplay between an extrinsic hormonal signal and an intrinsic transcription factor cascade.

Striatal adenosine A2A receptor neurons control active-period sleep via parvalbumin neurons in external globus pallidus.

  • Yuan XS
  • Elife
  • 2017 Oct 12

Literature context: er: A-11122, Life Technologies, RRID:AB_221569), goat anti-PV (1:3000, catalog


Abstract:

Dysfunction of the striatum is frequently associated with sleep disturbances. However, its role in sleep-wake regulation has been paid little attention even though the striatum densely expresses adenosine A2A receptors (A2ARs), which are essential for adenosine-induced sleep. Here we showed that chemogenetic activation of A2AR neurons in specific subregions of the striatum induced a remarkable increase in non-rapid eye movement (NREM) sleep. Anatomical mapping and immunoelectron microscopy revealed that striatal A2AR neurons innervated the external globus pallidus (GPe) in a topographically organized manner and preferentially formed inhibitory synapses with GPe parvalbumin (PV) neurons. Moreover, lesions of GPe PV neurons abolished the sleep-promoting effect of striatal A2AR neurons. In addition, chemogenetic inhibition of striatal A2AR neurons led to a significant decrease of NREM sleep at active period, but not inactive period of mice. These findings reveal a prominent contribution of striatal A2AR neuron/GPe PV neuron circuit in sleep control.

HDAC5 and Its Target Gene, Npas4, Function in the Nucleus Accumbens to Regulate Cocaine-Conditioned Behaviors.

  • Taniguchi M
  • Neuron
  • 2017 Sep 27

Literature context: 22, RRID:AB_221569 DARPP32, mouse Santa Cruz Biote


Abstract:

Individuals suffering from substance-use disorders develop strong associations between the drug's rewarding effects and environmental cues, creating powerful, enduring triggers for relapse. We found that dephosphorylated, nuclear histone deacetylase 5 (HDAC5) in the nucleus accumbens (NAc) reduced cocaine reward-context associations and relapse-like behaviors in a cocaine self-administration model. We also discovered that HDAC5 associates with an activity-sensitive enhancer of the Npas4 gene and negatively regulates NPAS4 expression. Exposure to cocaine and the test chamber induced rapid and transient NPAS4 expression in a small subpopulation of FOS-positive neurons in the NAc. Conditional deletion of Npas4 in the NAc significantly reduced cocaine conditioned place preference and delayed learning of the drug-reinforced action during cocaine self-administration, without affecting cue-induced reinstatement of drug seeking. These data suggest that HDAC5 and NPAS4 in the NAc are critically involved in reward-relevant learning and memory processes and that nuclear HDAC5 limits reinstatement of drug seeking independent of NPAS4.

Funding information:
  • NIDA NIH HHS - P01 DA008227()
  • NIDA NIH HHS - R01 DA027664()
  • NIDA NIH HHS - R01 DA032708()

Stable Positioning of Unc13 Restricts Synaptic Vesicle Fusion to Defined Release Sites to Promote Synchronous Neurotransmission.

  • Reddy-Alla S
  • Neuron
  • 2017 Sep 13

Literature context: ic, MA, A11122; AB Registry ID: RRID:AB_221569), mouse Nc82 = anti-BRPC-term (


Abstract:

Neural information processing depends on precisely timed, Ca2+-activated synaptic vesicle exocytosis from release sites within active zones (AZs), but molecular details are unknown. Here, we identify that the (M)Unc13-family member Unc13A generates release sites and show the physiological relevance of their restrictive AZ targeting. Super-resolution and intravital imaging of Drosophila neuromuscular junctions revealed that (unlike the other release factors Unc18 and Syntaxin-1A) Unc13A was stably and precisely positioned at AZs. Local Unc13A levels predicted single AZ activity. Different Unc13A portions selectively affected release site number, position, and functionality. An N-terminal fragment stably localized to AZs, displaced endogenous Unc13A, and reduced the number of release sites, while a C-terminal fragment generated excessive sites at atypical locations, resulting in reduced and delayed evoked transmission that displayed excessive facilitation. Thus, release site generation by the Unc13A C terminus and their specific AZ localization via the N terminus ensure efficient transmission and prevent ectopic, temporally imprecise release.

Golgi-independent secretory trafficking through recycling endosomes in neuronal dendrites and spines.

  • Bowen AB
  • Elife
  • 2017 Sep 6

Literature context: antibody GFP Invitrogen A11122; RRID:AB_221569 1:1000


Abstract:

Neurons face the challenge of regulating the abundance, distribution and repertoire of integral membrane proteins within their immense, architecturally complex dendritic arbors. While the endoplasmic reticulum (ER) supports dendritic translation, most dendrites lack the Golgi apparatus (GA), an essential organelle for conventional secretory trafficking. Thus, whether secretory cargo is locally trafficked in dendrites through a non-canonical pathway remains a fundamental question. Here we define the dendritic trafficking itinerary for key synaptic molecules in rat cortical neurons. Following ER exit, the AMPA-type glutamate receptor GluA1 and neuroligin 1 undergo spatially restricted entry into the dendritic secretory pathway and accumulate in recycling endosomes (REs) located in dendrites and spines before reaching the plasma membrane. Surprisingly, GluA1 surface delivery occurred even when GA function was disrupted. Thus, in addition to their canonical role in protein recycling, REs also mediate forward secretory trafficking in neuronal dendrites and spines through a specialized GA-independent trafficking network.

Funding information:
  • NCRR NIH HHS - S10 RR023381()
  • NIGMS NIH HHS - T32 GM007635()
  • NINDS NIH HHS - F30 NS092421()
  • NINDS NIH HHS - R01 NS082271()

Structural Basis for Substrate Recognition by the Ankyrin Repeat Domain of Human DHHC17 Palmitoyltransferase.

  • Verardi R
  • Structure
  • 2017 Sep 5

Literature context: -GFP Thermo Fisher Cat#A-11122; RRID:AB_221569 Mouse monoclonal anti-Snap25b T


Abstract:

DHHC enzymes catalyze palmitoylation, a major post-translational modification that regulates a number of key cellular processes. There are up to 24 DHHCs in mammals and hundreds of substrate proteins that get palmitoylated. However, how DHHC enzymes engage with their substrates is still poorly understood. There is currently no structural information about the interaction between any DHHC enzyme and protein substrates. In this study we have investigated the structural and thermodynamic bases of interaction between the ankyrin repeat domain of human DHHC17 (ANK17) and Snap25b. We solved a high-resolution crystal structure of the complex between ANK17 and a peptide fragment of Snap25b. Through structure-guided mutagenesis, we discovered key residues in DHHC17 that are critically important for interaction with Snap25b. We further extended our finding by showing that the same residues are also crucial for the interaction of DHHC17 with Huntingtin, one of its most physiologically relevant substrates.

Not all neuroligin 3 and 4X missense variants lead to significant functional inactivation.

  • Xu X
  • Brain Behav
  • 2017 Sep 26

Literature context: ntific Cat# A-11122 also A11122 RRID:AB_221569, US, Carlsbad, California),anti


Abstract:

INTRODUCTION: Neuroligins are postsynaptic cell adhesion molecules that interact with neurexins to regulate the fine balance between excitation and inhibition of synapses. Recently, accumulating evidence, involving mutation analysis, cellular assays, and mouse models, has suggested that neuroligin (NLGN) mutations affect synapse maturation and function. Previously, four missense variations [p.G426S (NLGN3), p.G84R (NLGN4X), p.Q162K (NLGN4X), and p.A283T (NLGN4X)] in four different unrelated patients have been identified by PCR and direct sequencing. METHODS: In this study, we analyzed the functional effect of these missense variations by in vitro experiment via the stable HEK293 cells expressing wild-type and mutant neuroligin. RESULTS: We found that the four mutations did not significantly impair the expression of neuroligin 3 and neuroligin 4X, and also did not measurably inhibit the neurexin 1-neuroligin interaction. These variants might play a modest role in the pathogenesis of autism or might simply be unreported infrequent polymorphisms. CONCLUSION: Our data suggest that these four previously described neuroligin mutations are not primary risk factors for autism.

A Circuit Node that Integrates Convergent Input from Neuromodulatory and Social Behavior-Promoting Neurons to Control Aggression in Drosophila.

  • Watanabe K
  • Neuron
  • 2017 Aug 30

Literature context: RRID:AB_221569 anti-GFP (mouse, clone 3E6) The


Abstract:

Diffuse neuromodulatory systems such as norepinephrine (NE) control brain-wide states such as arousal, but whether they control complex social behaviors more specifically is not clear. Octopamine (OA), the insect homolog of NE, is known to promote both arousal and aggression. We have performed a systematic, unbiased screen to identify OA receptor-expressing neurons (OARNs) that control aggression in Drosophila. Our results uncover a tiny population of male-specific aSP2 neurons that mediate a specific influence of OA on aggression, independent of any effect on arousal. Unexpectedly, these neurons receive convergent input from OA neurons and P1 neurons, a population of FruM+ neurons that promotes male courtship behavior. Behavioral epistasis experiments suggest that aSP2 neurons may constitute an integration node at which OAergic neuromodulation can bias the output of P1 neurons to favor aggression over inter-male courtship. These results have potential implications for thinking about the role of related neuromodulatory systems in mammals.

Funding information:
  • NIMH NIH HHS - MH084020(United States)

Early Integration of Temperature and Humidity Stimuli in the Drosophila Brain.

  • Frank DD
  • Curr. Biol.
  • 2017 Aug 7

Literature context: #A-11122; RRID:AB_221569 chicken an


Abstract:

The Drosophila antenna contains receptor neurons for mechanical, olfactory, thermal, and humidity stimuli. Neurons expressing the ionotropic receptor IR40a have been implicated in the selection of an appropriate humidity range [1, 2], but although previous work indicates that insect hygroreceptors may be made up by a "triad" of neurons (with a dry-, a cold-, and a humid-air-responding cell [3]), IR40a expression included only cold- and dry-air cells. Here, we report the identification of the humid-responding neuron that completes the hygrosensory triad in the Drosophila antenna. This cell type expresses the Ir68a gene, and Ir68a mutation perturbs humidity preference. Next, we follow the projections of Ir68a neurons to the brain and show that they form a distinct glomerulus in the posterior antennal lobe (PAL). In the PAL, a simple sensory map represents related features of the external environment with adjacent "hot," "cold," "dry," and "humid" glomeruli-an organization that allows for both unique and combinatorial sampling by central relay neurons. Indeed, flies avoided dry heat more robustly than humid heat, and this modulation was abolished by silencing of dry-air receptors. Consistently, at least one projection neuron type received direct synaptic input from both temperature and dry-air glomeruli. Our results further our understanding of humidity sensing in the Drosophila antenna, uncover a neuronal substrate for early sensory integration of temperature and humidity in the brain, and illustrate the logic of how ethologically relevant combinations of sensory cues can be processed together to produce adaptive behavioral responses.

Neural Circuit-Specialized Astrocytes: Transcriptomic, Proteomic, Morphological, and Functional Evidence.

  • Chai H
  • Neuron
  • 2017 Aug 2

Literature context: t#A11122; RRID:AB_221569 mouse anti


Abstract:

Astrocytes are ubiquitous in the brain and are widely held to be largely identical. However, this view has not been fully tested, and the possibility that astrocytes are neural circuit specialized remains largely unexplored. Here, we used multiple integrated approaches, including RNA sequencing (RNA-seq), mass spectrometry, electrophysiology, immunohistochemistry, serial block-face-scanning electron microscopy, morphological reconstructions, pharmacogenetics, and diffusible dye, calcium, and glutamate imaging, to directly compare adult striatal and hippocampal astrocytes under identical conditions. We found significant differences in electrophysiological properties, Ca2+ signaling, morphology, and astrocyte-synapse proximity between striatal and hippocampal astrocytes. Unbiased evaluation of actively translated RNA and proteomic data confirmed significant astrocyte diversity between hippocampal and striatal circuits. We thus report core astrocyte properties, reveal evidence for specialized astrocytes within neural circuits, and provide new, integrated database resources and approaches to explore astrocyte diversity and function throughout the adult brain. VIDEO ABSTRACT.

Modulation of occluding junctions alters the hematopoietic niche to trigger immune activation.

  • Khadilkar RJ
  • Elife
  • 2017 Aug 25

Literature context: 11122, Molecular Probes, A11122 RRID:AB_221569), mouse anti-Antennapedia (1:50


Abstract:

Stem cells are regulated by signals from their microenvironment, or niche. During Drosophila hematopoiesis, a niche regulates prohemocytes to control hemocyte production. Immune challenges activate cell-signalling to initiate the cellular and innate immune response. Specifically, certain immune challenges stimulate the niche to produce signals that induce prohemocyte differentiation. However, the mechanisms that promote prohemocyte differentiation subsequent to immune challenges are poorly understood. Here we show that bacterial infection induces the cellular immune response by modulating occluding-junctions at the hematopoietic niche. Occluding-junctions form a permeability barrier that regulates the accessibility of prohemocytes to niche derived signals. The immune response triggered by infection causes barrier breakdown, altering the prohemocyte microenvironment to induce immune cell production. Moreover, genetically induced barrier ablation provides protection against infection by activating the immune response. Our results reveal a novel role for occluding-junctions in regulating niche-hematopoietic progenitor signalling and link this mechanism to immune cell production following infection.

The CEP19-RABL2 GTPase Complex Binds IFT-B to Initiate Intraflagellar Transport at the Ciliary Base.

  • Kanie T
  • Dev. Cell
  • 2017 Jul 10

Literature context: t#A11122; RRID:AB_221569 Rabbit pol


Abstract:

Highly conserved intraflagellar transport (IFT) protein complexes direct both the assembly of primary cilia and the trafficking of signaling molecules. IFT complexes initially accumulate at the base of the cilium and periodically enter the cilium, suggesting an as-yet-unidentified mechanism that triggers ciliary entry of IFT complexes. Using affinity-purification and mass spectrometry of interactors of the centrosomal and ciliopathy protein, CEP19, we identify CEP350, FOP, and the RABL2B GTPase as proteins organizing the first known mechanism directing ciliary entry of IFT complexes. We discover that CEP19 is recruited to the ciliary base by the centriolar CEP350/FOP complex and then specifically captures GTP-bound RABL2B, which is activated via its intrinsic nucleotide exchange. Activated RABL2B then captures and releases its single effector, the intraflagellar transport B holocomplex, from the large pool of pre-docked IFT-B complexes, and thus initiates ciliary entry of IFT.

Mapping the Neural Substrates of Behavior.

  • Robie AA
  • Cell
  • 2017 Jul 13

Literature context: A-11122; RRID:AB_221569 Alexa Fluo


Abstract:

Assigning behavioral functions to neural structures has long been a central goal in neuroscience and is a necessary first step toward a circuit-level understanding of how the brain generates behavior. Here, we map the neural substrates of locomotion and social behaviors for Drosophila melanogaster using automated machine-vision and machine-learning techniques. From videos of 400,000 flies, we quantified the behavioral effects of activating 2,204 genetically targeted populations of neurons. We combined a novel quantification of anatomy with our behavioral analysis to create brain-behavior correlation maps, which are shared as browsable web pages and interactive software. Based on these maps, we generated hypotheses of regions of the brain causally related to sensory processing, locomotor control, courtship, aggression, and sleep. Our maps directly specify genetic tools to target these regions, which we used to identify a small population of neurons with a role in the control of walking.

Differentiation of Human Pluripotent Stem Cells into Colonic Organoids via Transient Activation of BMP Signaling.

  • Múnera JO
  • Cell Stem Cell
  • 2017 Jul 6

Literature context: A-11122, RRID:AB_221569 Goat Anti-


Abstract:

Gastric and small intestinal organoids differentiated from human pluripotent stem cells (hPSCs) have revolutionized the study of gastrointestinal development and disease. Distal gut tissues such as cecum and colon, however, have proved considerably more challenging to derive in vitro. Here we report the differentiation of human colonic organoids (HCOs) from hPSCs. We found that BMP signaling is required to establish a posterior SATB2+ domain in developing and postnatal intestinal epithelium. Brief activation of BMP signaling is sufficient to activate a posterior HOX code and direct hPSC-derived gut tube cultures into HCOs. In vitro, HCOs express colonic markers and contained colon-specific cell populations. Following transplantation into mice, HCOs undergo morphogenesis and maturation to form tissue that exhibits molecular, cellular, and morphologic properties of human colon. Together these data show BMP-dependent patterning of human hindgut into HCOs, which will be valuable for studying diseases including colitis and colon cancer.

Funding information:
  • NIAID NIH HHS - U19 AI116491()
  • NIBIB NIH HHS - U18 EB021780()
  • NIDDK NIH HHS - R01 DK070858()
  • NIDDK NIH HHS - R01 DK092456()
  • NIDDK NIH HHS - R01 DK098350()
  • NIDDK NIH HHS - R01 DK102551()
  • NIDDK NIH HHS - U01 DK103117()

A Peptidergic Circuit Links the Circadian Clock to Locomotor Activity.

  • King AN
  • Curr. Biol.
  • 2017 Jul 10

Literature context: A-11122; RRID:AB_221569 Mouse mono


Abstract:

The mechanisms by which clock neurons in the Drosophila brain confer an ∼24-hr rhythm onto locomotor activity are unclear, but involve the neuropeptide diuretic hormone 44 (DH44), an ortholog of corticotropin-releasing factor. Here we identified DH44 receptor 1 as the relevant receptor for rest:activity rhythms and mapped its site of action to hugin-expressing neurons in the subesophageal zone (SEZ). We traced a circuit that extends from Dh44-expressing neurons in the pars intercerebralis (PI) through hugin+ SEZ neurons to the ventral nerve cord. Hugin neuropeptide, a neuromedin U ortholog, also regulates behavioral rhythms. The DH44 PI-Hugin SEZ circuit controls circadian locomotor activity in a daily cycle but has minimal effect on feeding rhythms, suggesting that the circadian drive to feed can be separated from circadian locomotion. These findings define a linear peptidergic circuit that links the clock to motor outputs to modulate circadian control of locomotor activity.

Causal role for the subthalamic nucleus in interrupting behavior.

  • Fife KH
  • Elife
  • 2017 Jul 25

Literature context: rogen, A11122, RRID:AB_221569) overnight at 4°C with gentle a


Abstract:

Stopping or pausing in response to threats, conflicting information, or surprise is fundamental to behavior. Evidence across species has shown that the subthalamic nucleus (STN) is activated by scenarios involving stopping or pausing, yet evidence that the STN causally implements stops or pauses is lacking. Here we used optogenetics to activate or inhibit mouse STN to test its putative causal role. We first demonstrated that optogenetic stimulation of the STN excited its major projection targets. Next we showed that brief activation of STN projection neurons was sufficient to interrupt or pause a self-initiated bout of licking. Finally, we developed an assay in which surprise was used to interrupt licking, and showed that STN inhibition reduced the disruptive effect of surprise. Thus STN activation interrupts behavior, and blocking the STN blunts the interruptive effect of surprise. These results provide strong evidence that the STN is both necessary and sufficient for such forms of behavioral response suppression.

Funding information:
  • NIDA NIH HHS - R01 DA036612()
  • NINDS NIH HHS - R21 NS087496()

The laminar organization of the Drosophila ellipsoid body is semaphorin-dependent and prevents the formation of ectopic synaptic connections.

  • Xie X
  • Elife
  • 2017 Jun 20

Literature context: mofisher, RRID:AB_221569), mouse-an


Abstract:

The ellipsoid body (EB) in the Drosophila brain is a central complex (CX) substructure that harbors circumferentially laminated ring (R) neuron axons and mediates multifaceted sensory integration and motor coordination functions. However, what regulates R axon lamination and how lamination affects R neuron function remain unknown. We show here that the EB is sequentially innervated by small-field and large-field neurons and that early developing EB neurons play an important regulatory role in EB laminae formation. The transmembrane proteins semaphorin-1a (Sema-1a) and plexin A function together to regulate R axon lamination. R neurons recruit both GABA and GABA-A receptors to their axon terminals in the EB, and optogenetic stimulation coupled with electrophysiological recordings show that Sema-1a-dependent R axon lamination is required for preventing the spread of synaptic inhibition between adjacent EB lamina. These results provide direct evidence that EB lamination is critical for local pre-synaptic inhibitory circuit organization.

Funding information:
  • NINDS NIH HHS - P30 NS050274()
  • NINDS NIH HHS - R01 NS079584()

Lysosomal Degradation Is Required for Sustained Phagocytosis of Bacteria by Macrophages.

  • Wong CO
  • Cell Host Microbe
  • 2017 Jun 14

Literature context: #A-11122; RRID:AB_221569 GFP-Booste


Abstract:

Clearance of bacteria by macrophages involves internalization of the microorganisms into phagosomes, which are then delivered to endolysosomes for enzymatic degradation. These spatiotemporally segregated processes are not known to be functionally coupled. Here, we show that lysosomal degradation of bacteria sustains phagocytic uptake. In Drosophila and mammalian macrophages, lysosomal dysfunction due to loss of the endolysosomal Cl- transporter ClC-b/CLCN7 delayed degradation of internalized bacteria. Unexpectedly, defective lysosomal degradation of bacteria also attenuated further phagocytosis, resulting in elevated bacterial load. Exogenous application of bacterial peptidoglycans restored phagocytic uptake in the lysosomal degradation-defective mutants via a pathway requiring cytosolic pattern recognition receptors and NF-κB. Mammalian macrophages that are unable to degrade internalized bacteria also exhibit compromised NF-κB activation. Our findings reveal a role for phagolysosomal degradation in activating an evolutionarily conserved signaling cascade, which ensures that continuous uptake of bacteria is preceded by lysosomal degradation of microbes.

Funding information:
  • NIH HHS - P40 OD018537()
  • NINDS NIH HHS - R01 NS081301()
  • NINDS NIH HHS - R21 NS094860()

Feature Integration Drives Probabilistic Behavior in the Drosophila Escape Response.

  • von Reyn CR
  • Neuron
  • 2017 Jun 21

Literature context: A-11122; RRID:AB_221569 Rat anti-H


Abstract:

Animals rely on dedicated sensory circuits to extract and encode environmental features. How individual neurons integrate and translate these features into behavioral responses remains a major question. Here, we identify a visual projection neuron type that conveys predator approach information to the Drosophila giant fiber (GF) escape circuit. Genetic removal of this input during looming stimuli reveals that it encodes angular expansion velocity, whereas other input cell type(s) encode angular size. Motor program selection and timing emerge from linear integration of these two features within the GF. Linear integration improves size detection invariance over prior models and appropriately biases motor selection to rapid, GF-mediated escapes during fast looms. Our findings suggest feature integration, and motor control may occur as simultaneous operations within the same neuron and establish the Drosophila escape circuit as a model system in which these computations may be further dissected at the circuit level. VIDEO ABSTRACT.

Genetic specification of left-right asymmetry in the diaphragm muscles and their motor innervation.

  • Charoy C
  • Elife
  • 2017 Jun 22

Literature context: - A11122, RRID:AB_221569). Axon out


Abstract:

The diaphragm muscle is essential for breathing in mammals. Its asymmetric elevation during contraction correlates with morphological features suggestive of inherent left-right (L/R) asymmetry. Whether this asymmetry is due to L versus R differences in the muscle or in the phrenic nerve activity is unknown. Here, we have combined the analysis of genetically modified mouse models with transcriptomic analysis to show that both the diaphragm muscle and phrenic nerves have asymmetries, which can be established independently of each other during early embryogenesis in pathway instructed by Nodal, a morphogen that also conveys asymmetry in other organs. We further found that phrenic motoneurons receive an early L/R genetic imprint, with L versus R differences both in Slit/Robo signaling and MMP2 activity and in the contribution of both pathways to establish phrenic nerve asymmetry. Our study therefore demonstrates L-R imprinting of spinal motoneurons and describes how L/R modulation of axon guidance signaling helps to match neural circuit formation to organ asymmetry.

Funding information:
  • NIDCD NIH HHS - R01 DC009410()

MLL/WDR5 Complex Regulates Kif2A Localization to Ensure Chromosome Congression and Proper Spindle Assembly during Mitosis.

  • Ali A
  • Dev. Cell
  • 2017 Jun 19

Literature context: n A11122; RRID:AB_221569 Rabbit pol


Abstract:

Mixed-lineage leukemia (MLL), along with multisubunit (WDR5, RbBP5, ASH2L, and DPY30) complex catalyzes the trimethylation of H3K4, leading to gene activation. Here, we characterize a chromatin-independent role for MLL during mitosis. MLL and WDR5 localize to the mitotic spindle apparatus, and loss of function of MLL complex by RNAi results in defects in chromosome congression and compromised spindle formation. We report interaction of MLL complex with several kinesin and dynein motors. We further show that the MLL complex associates with Kif2A, a member of the Kinesin-13 family of microtubule depolymerase, and regulates the spindle localization of Kif2A during mitosis. We have identified a conserved WDR5 interaction (Win) motif, so far unique to the MLL family, in Kif2A. The Win motif of Kif2A engages in direct interactions with WDR5 for its spindle localization. Our findings highlight a non-canonical mitotic function of MLL complex, which may have a direct impact on chromosomal stability, frequently compromised in cancer.

A translational approach to capture gait signatures of neurological disorders in mice and humans.

  • Broom L
  • Sci Rep
  • 2017 Jun 12

Literature context: rogen; Antibodyregistry.org) or AB11122 (IgG fraction, 1:20,000; Invitrogen; Antibodyregistry.org). Following incubation with the


Abstract:

A method for capturing gait signatures in neurological conditions that allows comparison of human gait with animal models would be of great value in translational research. However, the velocity dependence of gait parameters and differences between quadruped and biped gait have made this comparison challenging. Here we present an approach that accounts for changes in velocity during walking and allows for translation across species. In mice, we represented spatial and temporal gait parameters as a function of velocity and established regression models that reproducibly capture the signatures of these relationships during walking. In experimental parkinsonism models, regression curves representing these relationships shifted from baseline, implicating changes in gait signatures, but with marked differences between models. Gait parameters in healthy human subjects followed similar strict velocity dependent relationships which were altered in Parkinson's patients in ways that resemble some but not all mouse models. This novel approach is suitable to quantify qualitative walking abnormalities related to CNS circuit dysfunction across species, identify appropriate animal models, and it provides important translational opportunities.

Funding information:
  • NINDS NIH HHS - R01 NS079623()

Septal Cholinergic Neuromodulation Tunes the Astrocyte-Dependent Gating of Hippocampal NMDA Receptors to Wakefulness.

  • Papouin T
  • Neuron
  • 2017 May 17

Literature context: . A11122; RRID:AB_221569 Goat polyc


Abstract:

The activation of the N-methyl D-aspartate receptor (NMDAR) is controlled by a glutamate-binding site and a distinct, independently regulated, co-agonist-binding site. In most brain regions, the NMDAR co-agonist is the astrocyte-derived gliotransmitter D-serine. We found that D-serine levels oscillate in mouse hippocampus as a function of wakefulness, in vitro and in vivo. This causes a full saturation of the NMDAR co-agonist site in the dark (active) phase that dissipates to sub-saturating levels during the light (sleep) phase, and influences learning performance throughout the day. We demonstrate that hippocampal astrocytes sense the wakefulness-dependent activity of septal cholinergic fibers through the α7-nicotinic acetylcholine receptor (α7nAChR), whose activation drives D-serine release. We conclude that astrocytes tune the gating of synaptic NMDARs to the vigilance state and demonstrate that this is directly relevant to schizophrenia, a disorder characterized by NMDAR and cholinergic hypofunctions. Indeed, bypassing cholinergic activity with a clinically tested α7nAChR agonist successfully enhances NMDAR activation. VIDEO ABSTRACT.

Funding information:
  • NIAAA NIH HHS - R01 AA020183()
  • NIMH NIH HHS - F31 MH106208()
  • NINDS NIH HHS - P30 NS047243()
  • NINDS NIH HHS - R01 NS037585()
  • NINDS NIH HHS - R37 NS037585()
  • NINDS NIH HHS - T32 NS061764()

A Brain-Region-Specific Neural Pathway Regulating Germinal Matrix Angiogenesis.

  • Ma S
  • Dev. Cell
  • 2017 May 22

Literature context: # A11122; RRID:AB_221569 Rabbit ant


Abstract:

Intimate communication between neural and vascular cells is critical for normal brain development and function. Germinal matrix (GM), a key primordium for the brain reward circuitry, is unique among brain regions for its distinct pace of angiogenesis and selective vulnerability to hemorrhage during development. A major neonatal condition, GM hemorrhage can lead to cerebral palsy, hydrocephalus, and mental retardation. Here we identify a brain-region-specific neural progenitor-based signaling pathway dedicated to regulating GM vessel development. This pathway consists of cell-surface sphingosine-1-phosphate receptors, an intracellular cascade including Gα co-factor Ric8a and p38 MAPK, and target gene integrin β8, which in turn regulates vascular TGF-β signaling. These findings provide insights into region-specific specialization of neurovascular communication, with special implications for deciphering potent early-life endocrine, as well as potential gut microbiota impacts on brain reward circuitry. They also identify tissue-specific molecular targets for GM hemorrhage intervention.

Funding information:
  • NINDS NIH HHS - R01 NS076729()

Macrophages Facilitate Electrical Conduction in the Heart.

  • Hulsmans M
  • Cell
  • 2017 Apr 20

Literature context: hicken anti-GFPAbcamCat# ab13970Rabbit anti-GFPThermo Fisher ScientificCat# A-11122Goat anti-guinea pig IgG biotinV


Abstract:

Organ-specific functions of tissue-resident macrophages in the steady-state heart are unknown. Here, we show that cardiac macrophages facilitate electrical conduction through the distal atrioventricular node, where conducting cells densely intersperse with elongated macrophages expressing connexin 43. When coupled to spontaneously beating cardiomyocytes via connexin-43-containing gap junctions, cardiac macrophages have a negative resting membrane potential and depolarize in synchrony with cardiomyocytes. Conversely, macrophages render the resting membrane potential of cardiomyocytes more positive and, according to computational modeling, accelerate their repolarization. Photostimulation of channelrhodopsin-2-expressing macrophages improves atrioventricular conduction, whereas conditional deletion of connexin 43 in macrophages and congenital lack of macrophages delay atrioventricular conduction. In the Cd11bDTR mouse, macrophage ablation induces progressive atrioventricular block. These observations implicate macrophages in normal and aberrant cardiac conduction.

Funding information:
  • NHLBI NIH HHS - K24 HL105780()
  • NHLBI NIH HHS - R01 HL092577()
  • NHLBI NIH HHS - R01 HL096576()
  • NHLBI NIH HHS - R01 HL114477()
  • NHLBI NIH HHS - R01 HL117829()
  • NHLBI NIH HHS - R01 HL125428()
  • NHLBI NIH HHS - R01 HL128264()
  • NHLBI NIH HHS - R01 HL131495()
  • NICHD NIH HHS - R01 HD069623()
  • NIDDK NIH HHS - P30 DK043351()
  • NIDDK NIH HHS - P30 DK057521()
  • NINDS NIH HHS - R01 NS084863()

Commensal Microbes and Hair Follicle Morphogenesis Coordinately Drive Treg Migration into Neonatal Skin.

  • Scharschmidt TC
  • Cell Host Microbe
  • 2017 Apr 12

Literature context: t#A11122; RRID:AB_221569 Goat anti-


Abstract:

Regulatory T cells (Tregs) are required to establish immune tolerance to commensal microbes. Tregs accumulate abruptly in the skin during a defined window of postnatal tissue development. However, the mechanisms mediating Treg migration to neonatal skin are unknown. Here we show that hair follicle (HF) development facilitates the accumulation of Tregs in neonatal skin and that upon skin entry these cells localize to HFs, a primary reservoir for skin commensals. Further, germ-free neonates had reduced skin Tregs indicating that commensal microbes augment Treg accumulation. We identified Ccl20 as a HF-derived, microbiota-dependent chemokine and found its receptor, Ccr6, to be preferentially expressed by Tregs in neonatal skin. The Ccl20-Ccr6 pathway mediated Treg migration in vitro and in vivo. Thus, HF morphogenesis, commensal microbe colonization, and local chemokine production work in concert to recruit Tregs into neonatal skin, thereby establishing this tissue Treg niche early in life.

Funding information:
  • NCI NIH HHS - P30 CA082103()
  • NIAMS NIH HHS - DP2 AR068130()
  • NIAMS NIH HHS - K08 AR062064()
  • NIAMS NIH HHS - K08 AR068409()
  • NIAMS NIH HHS - R21 AR066821()
  • NIDDK NIH HHS - P30 DK063720()

A Ratiometric Sensor for Imaging Insulin Secretion in Single β Cells.

  • Schifferer M
  • Cell Chem Biol
  • 2017 Apr 20

Literature context: < A11122; RRID:AB_221569 Rabbit mon


Abstract:

Despite the urgent need for assays to visualize insulin secretion there is to date no reliable method available for measuring insulin release from single cells. To address this need, we developed a genetically encoded reporter termed RINS1 based on proinsulin superfolder GFP (sfGFP) and mCherry fusions for monitoring insulin secretion. RINS1 expression in MIN6 β cells resulted in proper processing yielding single-labeled insulin species. Unexpectedly, glucose or drug stimulation of insulin secretion in β cells led to the preferential release of the insulin-sfGFP construct, while the mCherry-fused C-peptide remained trapped in exocytic granules. This physical separation was used to monitor glucose-stimulated insulin secretion ratiometrically by total internal reflection fluorescence microscopy in single MIN6 and primary mouse β cells. Further, RINS1 enabled parallel monitoring of pulsatile insulin release in tolbutamide-treated β cells, demonstrating the potential of RINS1 for investigations of antidiabetic drug candidates at the single-cell level.

Myrf ER-Bound Transcription Factors Drive C. elegans Synaptic Plasticity via Cleavage-Dependent Nuclear Translocation.

  • Meng J
  • Dev. Cell
  • 2017 Apr 24

Literature context: # A11122; RRID:AB_221569 Mouse anti


Abstract:

Synaptic refinement is a critical step in nervous system maturation, requiring a carefully timed reorganization and refinement of neuronal connections. We have identified myrf-1 and myrf-2, two C. elegans homologs of Myrf family transcription factors, as key regulators of synaptic rewiring. MYRF-1 and its paralog MYRF-2 are functionally redundant specifically in synaptic rewiring. They co-exist in the same protein complex and act cooperatively to regulate synaptic rewiring. We find that the MYRF proteins localize to the ER membrane and that they are cleaved into active N-terminal fragments, which then translocate into the nucleus to drive synaptic rewiring. Overexpression of active forms of MYRF is sufficient to accelerate synaptic rewiring. MYRF-1 and MYRF-2 are the first genes identified to be indispensable for promoting synaptic rewiring in C. elegans. These findings reveal a molecular mechanism underlying synaptic rewiring and developmental circuit plasticity.

Funding information:
  • Howard Hughes Medical Institute - P40 OD010440()
  • NIH HHS - R01 NS035546()

Neurogenic Radial Glia-like Cells in Meninges Migrate and Differentiate into Functionally Integrated Neurons in the Neonatal Cortex.

  • Bifari F
  • Cell Stem Cell
  • 2017 Mar 2

Literature context: #A-11122, RRID:AB_221569 Goat polyc


Abstract:

Whether new neurons are added in the postnatal cerebral cortex is still debated. Here, we report that the meninges of perinatal mice contain a population of neurogenic progenitors formed during embryonic development that migrate to the caudal cortex and differentiate into Satb2+ neurons in cortical layers II-IV. The resulting neurons are electrically functional and integrated into local microcircuits. Single-cell RNA sequencing identified meningeal cells with distinct transcriptome signatures characteristic of (1) neurogenic radial glia-like cells (resembling neural stem cells in the SVZ), (2) neuronal cells, and (3) a cell type with an intermediate phenotype, possibly representing radial glia-like meningeal cells differentiating to neuronal cells. Thus, we have identified a pool of embryonically derived radial glia-like cells present in the meninges that migrate and differentiate into functional neurons in the neonatal cerebral cortex.

Funding information:
  • NINDS NIH HHS - R01 NS036715(United States)

A Novel Human CAMK2A Mutation Disrupts Dendritic Morphology and Synaptic Transmission, and Causes ASD-Related Behaviors.

  • Stephenson JR
  • J. Neurosci.
  • 2017 Feb 22

Literature context: #A-11122 RRID:AB_221569, 1:3000-40


Abstract:

Characterizing the functional impact of novel mutations linked to autism spectrum disorder (ASD) provides a deeper mechanistic understanding of the underlying pathophysiological mechanisms. Here we show that a de novo Glu183 to Val (E183V) mutation in the CaMKIIα catalytic domain, identified in a proband diagnosed with ASD, decreases both CaMKIIα substrate phosphorylation and regulatory autophosphorylation, and that the mutated kinase acts in a dominant-negative manner to reduce CaMKIIα-WT autophosphorylation. The E183V mutation also reduces CaMKIIα binding to established ASD-linked proteins, such as Shank3 and subunits of l-type calcium channels and NMDA receptors, and increases CaMKIIα turnover in intact cells. In cultured neurons, the E183V mutation reduces CaMKIIα targeting to dendritic spines. Moreover, neuronal expression of CaMKIIα-E183V increases dendritic arborization and decreases both dendritic spine density and excitatory synaptic transmission. Mice with a knock-in CaMKIIα-E183V mutation have lower total forebrain CaMKIIα levels, with reduced targeting to synaptic subcellular fractions. The CaMKIIα-E183V mice also display aberrant behavioral phenotypes, including hyperactivity, social interaction deficits, and increased repetitive behaviors. Together, these data suggest that CaMKIIα plays a previously unappreciated role in ASD-related synaptic and behavioral phenotypes.SIGNIFICANCE STATEMENT Many autism spectrum disorder (ASD)-linked mutations disrupt the function of synaptic proteins, but no single gene accounts for >1% of total ASD cases. The molecular networks and mechanisms that couple the primary deficits caused by these individual mutations to core behavioral symptoms of ASD remain poorly understood. Here, we provide the first characterization of a mutation in the gene encoding CaMKIIα linked to a specific neuropsychiatric disorder. Our findings demonstrate that this ASD-linked de novo CAMK2A mutation disrupts multiple CaMKII functions, induces synaptic deficits, and causes ASD-related behavioral alterations, providing novel insights into the synaptic mechanisms contributing to ASD.

Funding information:
  • NCI NIH HHS - P30 CA068485()
  • NEI NIH HHS - P30 EY008126()
  • NICHD NIH HHS - U54 HD083211()
  • NIDDK NIH HHS - P30 DK020593()
  • NIDDK NIH HHS - P30 DK058404()
  • NIDDK NIH HHS - P60 DK020593()
  • NIDDK NIH HHS - U24 DK059637()
  • NIGMS NIH HHS - P41 GM103311()
  • NIMH NIH HHS - F31 MH109196()
  • NIMH NIH HHS - K01 MH107765()
  • NIMH NIH HHS - R01 MH063232()
  • NIMH NIH HHS - T32 MH065215()
  • NINDS NIH HHS - R01 NS078291()

Optogenetic Control of Synaptic Composition and Function.

  • Sinnen BL
  • Neuron
  • 2017 Feb 8

Literature context: #A-11122; RRID:AB_221569 Monoclonal


Abstract:

The molecular composition of the postsynaptic membrane is sculpted by synaptic activity. During synaptic plasticity at excitatory synapses, numerous structural, signaling, and receptor molecules concentrate at the postsynaptic density (PSD) to regulate synaptic strength. We developed an approach that uses light to tune the abundance of specific molecules in the PSD. We used this approach to investigate the relationship between the number of AMPA-type glutamate receptors in the PSD and synaptic strength. Surprisingly, adding more AMPA receptors to excitatory contacts had little effect on synaptic strength. Instead, we observed increased excitatory input through the apparent addition of new functional sites. Our data support a model where adding AMPA receptors is sufficient to activate synapses that had few receptors to begin with, but that additional remodeling events are required to strengthen established synapses. More broadly, this approach introduces the precise spatiotemporal control of optogenetics to the molecular control of synaptic function.

Funding information:
  • NCATS NIH HHS - UL1 TR001082()
  • NIAAA NIH HHS - T32 AA007464()
  • NICHD NIH HHS - T32 HD041697()
  • NIGMS NIH HHS - T32 GM007635()
  • NINDS NIH HHS - F30 NS092421()
  • NINDS NIH HHS - R01 NS040701()
  • NINDS NIH HHS - R01 NS082271()
  • NINDS NIH HHS - R56 NS040701()

A Brainstem-Spinal Cord Inhibitory Circuit for Mechanical Pain Modulation by GABA and Enkephalins.

  • François A
  • Neuron
  • 2017 Feb 22

Literature context: A-11122; RRID:AB_221569 Anti-GFP C


Abstract:

Pain thresholds are, in part, set as a function of emotional and internal states by descending modulation of nociceptive transmission in the spinal cord. Neurons of the rostral ventromedial medulla (RVM) are thought to critically contribute to this process; however, the neural circuits and synaptic mechanisms by which distinct populations of RVM neurons facilitate or diminish pain remain elusive. Here we used in vivo opto/chemogenetic manipulations and trans-synaptic tracing of genetically identified dorsal horn and RVM neurons to uncover an RVM-spinal cord-primary afferent circuit controlling pain thresholds. Unexpectedly, we found that RVM GABAergic neurons facilitate mechanical pain by inhibiting dorsal horn enkephalinergic/GABAergic interneurons. We further demonstrate that these interneurons gate sensory inputs and control pain through temporally coordinated enkephalin- and GABA-mediated presynaptic inhibition of somatosensory neurons. Our results uncover a descending disynaptic inhibitory circuit that facilitates mechanical pain, is engaged during stress, and could be targeted to establish higher pain thresholds. VIDEO ABSTRACT.

Role of Mitochondrial Metabolism in the Control of Early Lineage Progression and Aging Phenotypes in Adult Hippocampal Neurogenesis.

  • Beckervordersandforth R
  • Neuron
  • 2017 Feb 8

Literature context: # A-11122 RRID:AB_221569 goat anti-


Abstract:

Precise regulation of cellular metabolism is hypothesized to constitute a vital component of the developmental sequence underlying the life-long generation of hippocampal neurons from quiescent neural stem cells (NSCs). The identity of stage-specific metabolic programs and their impact on adult neurogenesis are largely unknown. We show that the adult hippocampal neurogenic lineage is critically dependent on the mitochondrial electron transport chain and oxidative phosphorylation machinery at the stage of the fast proliferating intermediate progenitor cell. Perturbation of mitochondrial complex function by ablation of the mitochondrial transcription factor A (Tfam) reproduces multiple hallmarks of aging in hippocampal neurogenesis, whereas pharmacological enhancement of mitochondrial function ameliorates age-associated neurogenesis defects. Together with the finding of age-associated alterations in mitochondrial function and morphology in NSCs, these data link mitochondrial complex function to efficient lineage progression of adult NSCs and identify mitochondrial function as a potential target to ameliorate neurogenesis-defects in the aging hippocampus.

Funding information:
  • NIMH NIH HHS - R01 MH105128()
  • NINDS NIH HHS - P01 NS097206()
  • NINDS NIH HHS - R35 NS097370()
  • NINDS NIH HHS - R37 NS047344()

Phosphorylation of β-arrestin2 at Thr383 by MEK underlies β-arrestin-dependent activation of Erk1/2 by GPCRs.

  • Cassier E
  • Elife
  • 2017 Feb 7

Literature context: antibody (RRID:AB_221569) from Invi


Abstract:

In addition to their role in desensitization and internalization of G protein-coupled receptors (GPCRs), β-arrestins are essential scaffolds linking GPCRs to Erk1/2 signaling. However, their role in GPCR-operated Erk1/2 activation differs between GPCRs and the underlying mechanism remains poorly characterized. Here, we show that activation of serotonin 5-HT2C receptors, which engage Erk1/2 pathway via a β-arrestin-dependent mechanism, promotes MEK-dependent β-arrestin2 phosphorylation at Thr383, a necessary step for Erk recruitment to the receptor/β-arrestin complex and Erk activation. Likewise, Thr383 phosphorylation is involved in β-arrestin-dependent Erk1/2 stimulation elicited by other GPCRs such as β2-adrenergic, FSH and CXCR4 receptors, but does not affect the β-arrestin-independent Erk1/2 activation by 5-HT4 receptor. Collectively, these data show that β-arrestin2 phosphorylation at Thr383 underlies β-arrestin-dependent Erk1/2 activation by GPCRs.

Leaky Gate Model: Intensity-Dependent Coding of Pain and Itch in the Spinal Cord.

  • Sun S
  • Neuron
  • 2017 Feb 22

Literature context: A-11122; RRID:AB_221569 mouse anti


Abstract:

Coding of itch versus pain has been heatedly debated for decades. However, the current coding theories (labeled line, intensity, and selectivity theory) cannot accommodate all experimental observations. Here we identified a subset of spinal interneurons, labeled by gastrin-releasing peptide (Grp), that receive direct synaptic input from both pain and itch primary sensory neurons. When activated, these Grp+ neurons generated rarely seen, simultaneous robust pain and itch responses that were intensity dependent. Accordingly, we propose a "leaky gate" model in which Grp+ neurons transmit both itch and weak pain signals; however, upon strong painful stimuli, the recruitment of endogenous opioids works to close this gate, reducing overwhelming pain generated by parallel pathways. Consistent with our model, loss of these Grp+ neurons increased pain responses while itch was decreased. Our new model serves as an example of non-monotonic coding in the spinal cord and better explains observations in human psychophysical studies.

Funding information:
  • NEI NIH HHS - R01 EY024704()
  • NIAID NIH HHS - R01 AI125743()
  • NIDCR NIH HHS - R01 DE022750()
  • NINDS NIH HHS - R01 NS054791()
  • NINDS NIH HHS - R01 NS070814()

p53 Modulates the Fate of Cardiac Progenitor Cells Ex Vivo and in the Diabetic Heart In Vivo.

  • Kannappan R
  • EBioMedicine
  • 2017 Feb 6

Literature context: A-11122, RRID:AB_221569; chicken p


Abstract:

p53 is an important modulator of stem cell fate, but its role in cardiac progenitor cells (CPCs) is unknown. Here, we tested the effects of a single extra-copy of p53 on the function of CPCs in the presence of oxidative stress mediated by doxorubicin in vitro and type-1 diabetes in vivo. CPCs were obtained from super-p53 transgenic mice (p53-tg), in which the additional allele is regulated in a manner similar to the endogenous protein. Old CPCs with increased p53 dosage showed a superior ability to sustain oxidative stress, repair DNA damage and restore cell division. With doxorubicin, a larger fraction of CPCs carrying an extra-copy of the p53 allele recruited γH2A.X reestablishing DNA integrity. Enhanced p53 expression resulted in a superior tolerance to oxidative stress in vivo by providing CPCs with defense mechanisms necessary to survive in the milieu of the diabetic heart; they engrafted in regions of tissue injury and in three days acquired the cardiomyocyte phenotype. The biological advantage provided by the increased dosage of p53 in CPCs suggests that this genetic strategy may be translated to humans to increase cellular engraftment and growth, critical determinants of successful cell therapy for the failing heart.

Funding information:
  • NIA NIH HHS - R01 AG026107()
  • NIA NIH HHS - R01 AG037490()

Resolving Heart Regeneration by Replacement Histone Profiling.

  • Goldman JA
  • Dev. Cell
  • 2017 Feb 27

Literature context: Rabbit anti-GFPLife TechnologiesA11122Goat anti-rabbit Alexa Fluor 488


Abstract:

Chromatin regulation is a principal mechanism governing animal development, yet it is unclear to what extent structural changes in chromatin underlie tissue regeneration. Non-mammalian vertebrates such as zebrafish activate cardiomyocyte (CM) division after tissue damage to regenerate lost heart muscle. Here, we generated transgenic zebrafish expressing a biotinylatable H3.3 histone variant in CMs and derived cell-type-specific profiles of histone replacement. We identified an emerging program of putative enhancers that revise H3.3 occupancy during regeneration, overlaid upon a genome-wide reduction of H3.3 from promoters. In transgenic reporter lines, H3.3-enriched elements directed gene expression in subpopulations of CMs. Other elements increased H3.3 enrichment and displayed enhancer activity in settings of injury- and/or Neuregulin1-elicited CM proliferation. Dozens of consensus sequence motifs containing predicted transcription factor binding sites were enriched in genomic regions with regeneration-responsive H3.3 occupancy. Thus, cell-type-specific regulatory programs of tissue regeneration can be revealed by genome-wide H3.3 profiling.

Funding information:
  • NHLBI NIH HHS - F32 HL120494()
  • NHLBI NIH HHS - K08 HL116485()
  • NHLBI NIH HHS - R01 HL081674()
  • NIGMS NIH HHS - R01 GM098461()

The Cellular and Synaptic Architecture of the Mechanosensory Dorsal Horn.

  • Abraira VE
  • Cell
  • 2017 Jan 12

Literature context: n A11122; RRID:AB_221569 Mouse anti


Abstract:

The deep dorsal horn is a poorly characterized spinal cord region implicated in processing low-threshold mechanoreceptor (LTMR) information. We report an array of mouse genetic tools for defining neuronal components and functions of the dorsal horn LTMR-recipient zone (LTMR-RZ), a role for LTMR-RZ processing in tactile perception, and the basic logic of LTMR-RZ organization. We found an unexpectedly high degree of neuronal diversity in the LTMR-RZ: seven excitatory and four inhibitory subtypes of interneurons exhibiting unique morphological, physiological, and synaptic properties. Remarkably, LTMRs form synapses on between four and 11 LTMR-RZ interneuron subtypes, while each LTMR-RZ interneuron subtype samples inputs from at least one to three LTMR classes, as well as spinal cord interneurons and corticospinal neurons. Thus, the LTMR-RZ is a somatosensory processing region endowed with a neuronal complexity that rivals the retina and functions to pattern the activity of ascending touch pathways that underlie tactile perception.

Funding information:
  • NCRR NIH HHS - S10 RR028832()
  • NIDA NIH HHS - P30 DA035756()
  • NIDA NIH HHS - R01 DA034022()
  • NIDA NIH HHS - R21 DA023643()
  • NIDCR NIH HHS - R01 DE022750()
  • NINDS NIH HHS - F32 NS077836()
  • NINDS NIH HHS - P01 NS079419()
  • NINDS NIH HHS - P30 NS072030()
  • NINDS NIH HHS - R35 NS097344()
  • NINDS NIH HHS - T32 NS007292()

An Actin Network Dispatches Ciliary GPCRs into Extracellular Vesicles to Modulate Signaling.

  • Nager AR
  • Cell
  • 2017 Jan 12

Literature context: 4DrebrinProgenMX823GFPInvitrogenA11122GLI3Suzie Scales6F5GPR161Saikat


Abstract:

Signaling receptors dynamically exit cilia upon activation of signaling pathways such as Hedgehog. Here, we find that when activated G protein-coupled receptors (GPCRs) fail to undergo BBSome-mediated retrieval from cilia back into the cell, these GPCRs concentrate into membranous buds at the tips of cilia before release into extracellular vesicles named ectosomes. Unexpectedly, actin and the actin regulators drebrin and myosin 6 mediate ectosome release from the tip of cilia. Mirroring signal-dependent retrieval, signal-dependent ectocytosis is a selective and effective process that removes activated signaling molecules from cilia. Congruently, ectocytosis compensates for BBSome defects as ectocytic removal of GPR161, a negative regulator of Hedgehog signaling, permits the appropriate transduction of Hedgehog signals in Bbs mutants. Finally, ciliary receptors that lack retrieval determinants such as the anorexigenic GPCR NPY2R undergo signal-dependent ectocytosis in wild-type cells. Our data show that signal-dependent ectocytosis regulates ciliary signaling in physiological and pathological contexts.

Funding information:
  • NCI NIH HHS - P30 CA124435()
  • NIGMS NIH HHS - R01 GM089933()

Filamin, a synaptic organizer in Drosophila, determines glutamate receptor composition and membrane growth.

  • Lee G
  • Elife
  • 2016 Dec 3

Literature context: nologies (RRID:AB_221569); at 1:100


Abstract:

Filamin is a scaffolding protein that functions in many cells as an actin-crosslinker. FLN90, an isoform of the Drosophila ortholog Filamin/cheerio that lacks the actin-binding domain, is here shown to govern the growth of postsynaptic membrane folds and the composition of glutamate receptor clusters at the larval neuromuscular junction. Genetic and biochemical analyses revealed that FLN90 is present surrounding synaptic boutons. FLN90 is required in the muscle for localization of the kinase dPak and, downstream of dPak, for localization of the GTPase Ral and the exocyst complex to this region. Consequently, Filamin is needed for growth of the subsynaptic reticulum. In addition, in the absence of filamin, type-A glutamate receptor subunits are lacking at the postsynapse, while type-B subunits cluster correctly. Receptor composition is dependent on dPak, but independent of the Ral pathway. Thus two major aspects of synapse formation, morphological plasticity and subtype-specific receptor clustering, require postsynaptic Filamin.

Funding information:
  • NIDCD NIH HHS - R01DC012931(United States)

A conserved bacterial protein induces pancreatic beta cell expansion during zebrafish development.

  • Hill JH
  • Elife
  • 2016 Dec 13

Literature context: A-11122, RRID:AB_221569), mouse an


Abstract:

Resident microbes play important roles in the development of the gastrointestinal tract, but their influence on other digestive organs is less well explored. Using the gnotobiotic zebrafish, we discovered that the normal expansion of the pancreatic β cell population during early larval development requires the intestinal microbiota and that specific bacterial members can restore normal β cell numbers. These bacteria share a gene that encodes a previously undescribed protein, named herein BefA (β Cell Expansion Factor A), which is sufficient to induce β cell proliferation in developing zebrafish larvae. Homologs of BefA are present in several human-associated bacterial species, and we show that they have conserved capacity to stimulate β cell proliferation in larval zebrafish. Our findings highlight a role for the microbiota in early pancreatic β cell development and suggest a possible basis for the association between low diversity childhood fecal microbiota and increased diabetes risk.

Chemogenetic inhibition of the medial prefrontal cortex reverses the effects of REM sleep loss on sucrose consumption.

  • McEown K
  • Elife
  • 2016 Dec 6

Literature context: r Probes, RRID:AB_221569, lot numbe


Abstract:

Rapid eye movement (REM) sleep loss is associated with increased consumption of weight-promoting foods. The prefrontal cortex (PFC) is thought to mediate reward anticipation. However, the precise role of the PFC in mediating reward responses to highly palatable foods (HPF) after REM sleep deprivation is unclear. We selectively reduced REM sleep in mice over a 25-48 hr period and chemogenetically inhibited the medial PFC (mPFC) by using an altered glutamate-gated and ivermectin-gated chloride channel that facilitated neuronal inhibition through hyperpolarizing infected neurons. HPF consumption was measured while the mPFC was inactivated and REM sleep loss was induced. We found that REM sleep loss increased HPF consumption compared to control animals. However, mPFC inactivation reversed the effect of REM sleep loss on sucrose consumption without affecting fat consumption. Our findings provide, for the first time, a causal link between REM sleep, mPFC function and HPF consumption.

Funding information:
  • NINDS NIH HHS - R01-NS 07312401(United States)

Ciliary transcription factors and miRNAs precisely regulate Cp110 levels required for ciliary adhesions and ciliogenesis.

  • Walentek P
  • Elife
  • 2016 Sep 13

Literature context: in were immunoprecipitated with antibodies directed against GFP (Invitrogen; #{"type":"entrez-n


Abstract:

Upon cell cycle exit, centriole-to-basal body transition facilitates cilia formation. The centriolar protein Cp110 is a regulator of this process and cilia inhibitor, but its positive roles in ciliogenesis remain poorly understood. Using Xenopus we show that Cp110 inhibits cilia formation at high levels, while optimal levels promote ciliogenesis. Cp110 localizes to cilia-forming basal bodies and rootlets, and is required for ciliary adhesion complexes that facilitate Actin interactions. The opposing roles of Cp110 in ciliation are generated in part by coiled-coil domains that mediate preferential binding to centrioles over rootlets. Because of its dual role in ciliogenesis, Cp110 levels must be precisely controlled. In multiciliated cells, this is achieved by both transcriptional and post-transcriptional regulation through ciliary transcription factors and microRNAs, which activate and repress cp110 to produce optimal Cp110 levels during ciliogenesis. Our data provide novel insights into how Cp110 and its regulation contribute to development and cell function.

Funding information:
  • European Research Council - 293681(International)

Postembryonic lineages of the Drosophila ventral nervous system: Neuroglian expression reveals the adult hemilineage associated fiber tracts in the adult thoracic neuromeres.

  • Shepherd D
  • J. Comp. Neurol.
  • 2016 Sep 1

Literature context: o. A11122 RRID:AB_221569), 1:40 rat


Abstract:

During larval life most of the thoracic neuroblasts (NBs) in Drosophila undergo a second phase of neurogenesis to generate adult-specific neurons that remain in an immature, developmentally stalled state until pupation. Using a combination of MARCM and immunostaining with a neurotactin antibody, Truman et al. (2004; Development 131:5167-5184) identified 24 adult-specific NB lineages within each thoracic hemineuromere of the larval ventral nervous system (VNS), but because of the neurotactin labeling of lineage tracts disappearing early in metamorphosis, they were unable extend the identification of these lineages into the adult. Here we show that immunostaining with an antibody against the cell adhesion molecule neuroglian reveals the same larval secondary lineage projections through metamorphosis and bfy identifying each neuroglian-positive tract at selected stages we have traced the larval hemilineage tracts for all three thoracic neuromeres through metamorphosis into the adult. To validate tract identifications we used the genetic toolkit developed by Harris et al. (2015; Elife 4) to preserve hemilineage-specific GAL4 expression patterns from larval into the adult stage. The immortalized expression proved a powerful confirmation of the analysis of the neuroglian scaffold. This work has enabled us to directly link the secondary, larval NB lineages to their adult counterparts. The data provide an anatomical framework that 1) makes it possible to assign most neurons to their parent lineage and 2) allows more precise definitions of the neuronal organization of the adult VNS based in developmental units/rules. J. Comp. Neurol. 524:2677-2695, 2016. © 2016 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc.

Funding information:
  • NIA NIH HHS - R01 AG044486(United States)
  • NIMH NIH HHS - U54 MH084690(United States)

EphA4 has distinct functionality from EphA7 in the corticothalamic system during mouse brain development.

  • Son AI
  • J. Comp. Neurol.
  • 2016 Jul 1

Literature context: . A11122; RRID:AB_221569; Invitroge


Abstract:

Deciphering the molecular basis for guiding specific aspects of neocortical development remains a challenge because of the complexity of histogenic events and the vast array of protein interactions mediating these events. The Eph family of receptor tyrosine kinases is implicated in a number of neurodevelopmental activities. Eph receptors have been known to be capable of responding to several ephrin ligands within their subgroups, often eliciting similar downstream effects. However, several recent studies have indicated specificity between receptor-ligand pairs within each subfamily, the functional relevance of which is not defined. Here we show that a receptor of the EphA subfamily, EphA4, has effects distinct from those of its close relative, EphA7, in the developing brain. Both EphA4 and EphA7 interact similarly with corresponding ligands expressed in the developing neocortex. However, only EphA7 shows strong interaction with ligands in the somatosensory thalamic nuclei; EphA4 affects only cortical neuronal migration, with no visible effects on the guidance of corticothalamic (CT) axons, whereas EphA7 affects both cortical neuronal migration and CT axon guidance. Our data provide new evidence that Eph receptors in the same subfamily are not simply interchangeable but are functionally specified through selective interactions with distinct ligands in vivo. J. Comp. Neurol. 524:2080-2092, 2016. © 2015 Wiley Periodicals, Inc.

Interstitial branch formation within the red nucleus by deep cerebellar nuclei-derived commissural axons during target recognition.

  • Hara S
  • J. Comp. Neurol.
  • 2016 Apr 1

Literature context: 49920;AB_221569;RRID:AB_24


Abstract:

Target recognition by developing axons is one of the fundamental steps for establishing the proper pattern of neuronal connectivity during development. However, knowledge of the mechanisms that underlie this critical event is still limited. In this study, to examine how commissural axons in vertebrates recognize their targets after crossing the midline, we analyzed in detail the behavior of postcrossing commissural axons derived from the deep cerebellar nuclei (DCN) in the developing mouse cerebellum. For this, we employed a cell-type-specific genetic labeling approach to selectively visualize DCN axons during the time when these axons project to the red nucleus (RN), one of the well-characterized targets of DCN axons. We found that, when DCN axons initially entered the RN at its caudal end, these axons continued to grow rostrally through the RN without showing noticeable morphological signs of axon branching. Interestingly, after a delay, DCN axons started forming interstitial branches from the portion of the axon shaft selectively within the RN. Because commissural axons acquire responsiveness to several guidance cues when they cross the midline, we further addressed whether midline crossing is a prerequisite for subsequent targeting by using a Robo3 knockdown strategy. We found that DCN axons were still capable of forming interstitial branches within the RN even in the absence of midline crossing. These results therefore suggest that the mechanism of RN recognition by DCN axons involves a delayed interstitial branching, and that these axons possess an intrinsic ability to respond to the target-derived cues irrespective of midline crossing.

Funding information:
  • NIA NIH HHS - R01 AG022381(United States)

Total protein is an effective loading control for cerebrospinal fluid western blots.

  • Collins MA
  • J. Neurosci. Methods
  • 2015 Aug 15

Literature context: land, NY; RRID:AB_221569), chicken-


Abstract:

BACKGROUND: Cerebrospinal fluid (CSF) has been used to identify biomarkers of neurological disease. CSF protein biomarkers identified by high-throughput methods, however, require further validation. While Western blotting (WB) is well-suited to this task, the lack of a validated loading control for CSF WB limits the method's accuracy. NEW METHOD: We investigated the use of total protein (TP) as a CSF WB loading control. Using iodine-based reversible membrane staining, we determined the linear range and consistency of the CSF TP signal. We then spiked green fluorescent protein (GFP) into CSF to create defined sample-to-sample differences in GFP levels that were measured by WB before and after TP loading correction. Levels of CSF complement C3 and cystatin C measured by WB with TP loading correction and ELISA in amyotrophic lateral sclerosis and healthy control CSF samples were then compared. RESULTS: CSF WB with the TP loading control accurately detected defined differences in GFP levels and corrected for simulated loading errors. Individual CSF sample Western blot and ELISA measurements of complement C3 and cystatin C were significantly correlated and the methods showed a comparable ability to detect between-groups differences. COMPARISON WITH EXISTING METHOD: CSF TP staining has a greater linear dynamic range and sample-to-sample consistency than albumin, a commonly used CSF loading control. The method accurately corrects for simulated errors in loading and improves the sensitivity of CSF WB compared to using no loading control. CONCLUSIONS: The TP staining loading control improves the sensitivity and accuracy of CSF WB results.

Targeted inhibition of the Shroom3-Rho kinase protein-protein interaction circumvents Nogo66 to promote axon outgrowth.

  • Dickson HM
  • BMC Neurosci
  • 2015 Jun 16

Literature context: t# A11122 RRID:AB_221569] followed


Abstract:

BACKGROUND: Inhibitory molecules in the adult central nervous system, including NogoA, impede neural repair by blocking axon outgrowth. The actin-myosin regulatory protein Shroom3 directly interacts with Rho kinase and conveys axon outgrowth inhibitory signals from Nogo66, a C-terminal inhibitory domain of NogoA. The purpose of this study was to identify small molecules that block the Shroom3-Rho kinase protein-protein interaction as a means to modulate NogoA signaling and, in the longer term, enhance axon outgrowth during neural repair. RESULTS: A high throughput screen for inhibitors of the Shroom3-Rho kinase protein-protein interaction identified CCG-17444 (Chem ID: 2816053). CCG-17444 inhibits the Shroom3-Rho kinase interaction in vitro with micromolar potency. This compound acts through an irreversible, covalent mechanism of action, targeting Shroom3 Cys1816 to inhibit the Shroom3-Rho kinase protein-protein interaction. Inhibition of the Shroom3-Rho kinase protein-protein interaction with CCG-17444 counteracts the inhibitory action of Nogo66 and enhances neurite outgrowth. CONCLUSIONS: This study identifies a small molecule inhibitor of the Shroom3-Rho kinase protein-protein interaction that circumvents the inhibitory action of Nogo66 in neurons. Identification of a small molecule compound that blocks the Shroom3-Rho kinase protein-protein interaction provides a first step towards a potential new strategy for enhancing neural repair.

Cell-specific and developmental expression of lectican-cleaving proteases in mouse hippocampus and neocortex.

  • Levy C
  • J. Comp. Neurol.
  • 2015 Mar 1

Literature context: (RRID:AB_221569)


Abstract:

Mounting evidence has demonstrated that a specialized extracellular matrix exists in the mammalian brain and that this glycoprotein-rich matrix contributes to many aspects of brain development and function. The most prominent supramolecular assemblies of these extracellular matrix glycoproteins are perineuronal nets, specialized lattice-like structures that surround the cell bodies and proximal neurites of select classes of interneurons. Perineuronal nets are composed of lecticans, a family of chondroitin sulfate proteoglycans that includes aggrecan, brevican, neurocan, and versican. These lattice-like structures emerge late in postnatal brain development, coinciding with the ending of critical periods of brain development. Despite our knowledge of the presence of lecticans in perineuronal nets and their importance in regulating synaptic plasticity, we know little about the development or distribution of the extracellular proteases that are responsible for their cleavage and turnover. A subset of a large family of extracellular proteases (called a disintegrin and metalloproteinase with thrombospondin motifs [ADAMTS]) is responsible for endogenously cleaving lecticans. We therefore explored the expression pattern of two aggrecan-degrading ADAMTS family members, ADAMTS15 and ADAMTS4, in the hippocampus and neocortex. Here, we show that both lectican-degrading metalloproteases are present in these brain regions and that each exhibits a distinct temporal and spatial expression pattern. Adamts15 mRNA is expressed exclusively by parvalbumin-expressing interneurons during synaptogenesis, whereas Adamts4 mRNA is exclusively generated by telencephalic oligodendrocytes during myelination. Thus, ADAMTS15 and ADAMTS4 not only exhibit unique cellular expression patterns but their developmental upregulation by these cell types coincides with critical aspects of neural development.

Rat subthalamic nucleus and zona incerta share extensively overlapped representations of cortical functional territories.

  • Kita T
  • J. Comp. Neurol.
  • 2014 Dec 15

Literature context: tudy are listed in Table 1. The GFP antibody is a rabbit polyclonal raised d


Abstract:

The subthalamic nucleus (STN) and the zona incerta (ZI) are two major structures of the subthalamus. The STN has strong connections between the basal ganglia and related nuclei. The ZI has strong connections between brainstem reticular nuclei, sensory nuclei, and nonspecific thalamic nuclei. Both the STN and ZI receive heavy projections from a subgroup of layer V neurons in the cerebral cortex. The major goal of this study was to investigate the following two questions about the cortico-subthalamic projections using the lentivirus anterograde tracing method in the rat: 1) whether cortical projections to the STN and ZI have independent functional organizations or a global organization encompassing the entire subthalamus as a whole; and 2) how the cortical functional zones are represented in the subthalamus. This study revealed that the subthalamus receives heavy projections from the motor and sensory cortices, that the cortico-subthalamic projections have a large-scale functional organization that encompasses both the STN and two subdivisions of the ZI, and that the group of cortical axons that originate from a particular area of the cortex sequentially innervate and form separate terminal fields in the STN and ZI. The terminal zones formed by different cortical functional areas have highly overlapped and fuzzy borders, as do the somatotopic representations of the sensorimotor cortex in the subthalamus. The present study suggests that the layer V neurons in the wide areas of the sensorimotor cortex simultaneously control STN and ZI neurons. Together with other known afferent and efferent connections, possible new functionality of the STN and ZI is discussed.

Cell type-specific spatial and functional coupling between mammalian brain Kv2.1 K+ channels and ryanodine receptors.

  • Mandikian D
  • J. Comp. Neurol.
  • 2014 Oct 15

Literature context: t# A11122 RRID:AB_221569) was raise


Abstract:

The Kv2.1 voltage-gated K+ channel is widely expressed throughout mammalian brain, where it contributes to dynamic activity-dependent regulation of intrinsic neuronal excitability. Here we show that somatic plasma membrane Kv2.1 clusters are juxtaposed to clusters of intracellular ryanodine receptor (RyR) Ca2+ -release channels in mouse brain neurons, most prominently in medium spiny neurons (MSNs) of the striatum. Electron microscopy-immunogold labeling shows that in MSNs, plasma membrane Kv2.1 clusters are adjacent to subsurface cisternae, placing Kv2.1 in close proximity to sites of RyR-mediated Ca2+ release. Immunofluorescence labeling in transgenic mice expressing green fluorescent protein in specific MSN populations reveals the most prominent juxtaposed Kv2.1:RyR clusters in indirect pathway MSNs. Kv2.1 in both direct and indirect pathway MSNs exhibits markedly lower levels of labeling with phosphospecific antibodies directed against the S453, S563, and S603 phosphorylation site compared with levels observed in neocortical neurons, although labeling for Kv2.1 phosphorylation at S563 was significantly lower in indirect pathway MSNs compared with those in the direct pathway. Finally, acute stimulation of RyRs in heterologous cells causes a rapid hyperpolarizing shift in the voltage dependence of activation of Kv2.1, typical of Ca2+ /calcineurin-dependent Kv2.1 dephosphorylation. Together, these studies reveal that striatal MSNs are distinct in their expression of clustered Kv2.1 at plasma membrane sites juxtaposed to intracellular RyRs, as well as in Kv2.1 phosphorylation state. Differences in Kv2.1 expression and phosphorylation between MSNs in direct and indirect pathways provide a cell- and circuit-specific mechanism for coupling intracellular Ca2+ release to phosphorylation-dependent regulation of Kv2.1 to dynamically impact intrinsic excitability.

Funding information:
  • NCRR NIH HHS - R24-RR016344(United States)

Lactoferrin-iCre: a new mouse line to study uterine epithelial gene function.

  • Daikoku T
  • Endocrinology
  • 2014 Jul 21

Literature context:


Abstract:

Transgenic animal models are valuable for studying gene function in various tissue compartments. Mice with conditional deletion of genes in the uterus using the Cre-loxP system serve as powerful tools to study uterine biology. The uterus is comprised of 3 major tissue types: myometrium, stroma, and epithelium. Proliferation and differentiation in each uterine cell type are differentially regulated by ovarian hormones, resulting in spatiotemporal control of gene expression. Therefore, examining gene function in each uterine tissue type will provide more meaningful information regarding uterine biology during pregnancy and disease states. Although currently available Cre mouse lines have been very useful in exploring functions of specific genes in uterine biology, overlapping expression of these Cre lines in more than 1 tissue type and in other reproductive organs sometimes makes interpretation of results difficult. In this article, we report the generation of a new iCre knock-in mouse line, in which iCre is expressed from endogenous lactoferrin (Ltf) promoter. Ltf-iCre mice primarily direct recombination in the uterine epithelium in adult females and in immature females after estrogen treatment. These mice will allow for specific interrogation of gene function in the mature uterine epithelium, providing a helpful tool to uncover important aspects of uterine biology.

Funding information:
  • NIDDK NIH HHS - R37 DK050107(United States)

Odd-skipped labels a group of distinct neurons associated with the mushroom body and optic lobe in the adult Drosophila brain.

  • Levy P
  • J. Comp. Neurol.
  • 2014 Jun 11

Literature context:


Abstract:

Olfactory processing has been intensively studied in Drosophila melanogaster. However, we still know little about the descending neural pathways from the higher order processing centers and how these connect with other neural circuits. Here we describe, in detail, the adult projections patterns that arise from a cluster of 78 neurons, defined by the expression of the Odd-skipped transcription factor. We term these neurons Odd neurons. By using expression of genetically encoded axonal and dendritic markers, we show that a subset of the Odd neurons projects dendrites into the calyx of the mushroom body (MB) and axons into the inferior protocerebrum. We exclude the possibility that the Odd neurons are part of the well-known Kenyon cells whose projections form the MB and conclude that the Odd neurons belong to a previously not described class of extrinsic MB neurons. In addition, three of the Odd neurons project into the lobula plate of the optic lobe, and two of these cells extend axons ipsi- and contralaterally in the brain. Anatomically, these cells do not resemble any previously described lobula plate tangential cells (LPTCs) in Drosophila. We show that the Odd neurons are predominantly cholinergic but also include a small number of γ-aminobutyric acid (GABA)ergic neurons. Finally, we provide evidence that the Odd neurons are a hemilineage, suggesting they are born from a defined set of neuroblasts. Our anatomical analysis hints at the possibility that subgroups of Odd neurons could be involved in olfactory and visual processing.

Funding information:
  • NHGRI NIH HHS - 5 T32 HG000044(United States)

Phosphorylation of synapsin I by cyclin-dependent kinase-5 sets the ratio between the resting and recycling pools of synaptic vesicles at hippocampal synapses.

  • Verstegen AM
  • J. Neurosci.
  • 2014 May 21

Literature context: #A11122, RRID:AB_221569; Invitroge


Abstract:

Cyclin-dependent kinase-5 (Cdk5) was reported to downscale neurotransmission by sequestering synaptic vesicles (SVs) in the release-reluctant resting pool, but the molecular targets mediating this activity remain unknown. Synapsin I (SynI), a major SV phosphoprotein involved in the regulation of SV trafficking and neurotransmitter release, is one of the presynaptic substrates of Cdk5, which phosphorylates it in its C-terminal region at Ser(549) (site 6) and Ser(551) (site 7). Here we demonstrate that Cdk5 phosphorylation of SynI fine tunes the recruitment of SVs to the active recycling pool and contributes to the Cdk5-mediated homeostatic responses. Phosphorylation of SynI by Cdk5 is physiologically regulated and enhances its binding to F-actin. The effects of Cdk5 inhibition on the size and depletion kinetics of the recycling pool, as well as on SV distribution within the nerve terminal, are virtually abolished in mouse SynI knock-out (KO) neurons or in KO neurons expressing the dephosphomimetic SynI mutants at sites 6,7 or site 7 only. The observation that the single site-7 mutant phenocopies the effects of the deletion of SynI identifies this site as the central switch in mediating the synaptic effects of Cdk5 and demonstrates that SynI is necessary and sufficient for achieving the effects of the kinase on SV trafficking. The phosphorylation state of SynI by Cdk5 at site 7 is regulated during chronic modification of neuronal activity and is an essential downstream effector for the Cdk5-mediated homeostatic scaling.

Development of myenteric cholinergic neurons in ChAT-Cre;R26R-YFP mice.

  • Hao MM
  • J. Comp. Neurol.
  • 2013 Oct 1

Literature context:


Abstract:

Cholinergic neurons are the major excitatory neurons of the enteric nervous system (ENS), and include intrinsic sensory neurons, interneurons, and excitatory motor neurons. Cholinergic neurons have been detected in the embryonic ENS; however, the development of these neurons has been difficult to study as they are difficult to detect prior to birth using conventional immunohistochemistry. In this study we used ChAT-Cre;R26R-YFP mice to examine the development of cholinergic neurons in the gut of embryonic and postnatal mice. Cholinergic (YFP+) neurons were first detected at embryonic day (E)11.5, and the proportion of cholinergic neurons gradually increased during pre- and postnatal development. At birth, myenteric cholinergic neurons comprised less than half of their adult proportions in the small intestine (25% of myenteric neurons were YFP+ at P0 compared to 62% in adults). The earliest cholinergic neurons appear to mainly project anally. Projections into the presumptive circular muscle were first observed at E14.5. A subpopulation of cholinergic neurons coexpress calbindin through embryonic and postnatal development, but only a small proportion coexpressed neuronal nitric oxide synthase. Our study shows that cholinergic neurons in the ENS develop over a protracted period of time.

Funding information:
  • NIDDK NIH HHS - DK84142(United States)
  • Wellcome Trust - 085532(United Kingdom)

Conditional viral tracing reveals that steroidogenic factor 1-positive neurons of the dorsomedial subdivision of the ventromedial hypothalamus project to autonomic centers of the hypothalamus and hindbrain.

  • Lindberg D
  • J. Comp. Neurol.
  • 2013 Oct 1

Literature context:


Abstract:

Excitation of neurons in the ventromedial hypothalamus (VMH), especially those residing in the dorsomedial part of the nucleus (VMHdm), evokes sympathetic nervous system (SNS) outflow, modulating a number of physiological functions including feeding and blood glucose homeostasis. However, the anatomical basis of VMH-mediated SNS activation has thus far proved elusive. To understand how VMH neurons exercise output functions and describe an anatomical link between these neurons and the SNS, we identified downstream neural targets of the VMHdm by injecting an adenoviral vector encoding Cre recombinase (Cre)-regulated farnesylated green fluorescent protein (GFPf ) into the VMHdm of mice that express Cre in neurons expressing the VMH-specific transcription factor steroidogenic factor 1 (SF1). We confirm previously described projection patterns of the VMHdm and report the existence of a formerly unidentified projection pathway to a number of autonomic centers in the brainstem. These VMH efferents travel caudally through the periaqueductal gray (PAG) and then ventrally through the lateral lemniscus to the ventral surface of the brain, where they eventually reach caudal autonomic centers including the C1 catecholamine cell group of the rostral ventrolateral medulla (RVLM) and the nucleus of the solitary tract (NTS), where VMH efferents make close contacts with catecholaminergic neurons. We also found that VMHdm fibers reach a number of brainstem areas, including the retrotrapezoid nucleus (RTN), which are important in regulating respiration. Thus, the present study indicates that the VMH may modulate sympathetic and autonomic activity via synaptic contacts in the RTN, NTS, and RVLM and provides significant anatomical evidence to support a role of the VMH in respiratory regulation.

Funding information:
  • NHGRI NIH HHS - U54 HG004576(United States)

Identification of multisegmental nociceptive afferents that modulate locomotor circuits in the neonatal mouse spinal cord.

  • Mandadi S
  • J. Comp. Neurol.
  • 2013 Aug 15

Literature context:


Abstract:

Compared to proprioceptive afferent collateral projections, less is known about the anatomical, neurochemical, and functional basis of nociceptive collateral projections modulating lumbar central pattern generators (CPG). Quick response times are critical to ensure rapid escape from aversive stimuli. Furthermore, sensitization of nociceptive afferent pathways can contribute to a pathological activation of motor circuits. We investigated the extent and role of collaterals of capsaicin-sensitive nociceptive sacrocaudal afferent (nSCA) nerves that directly ascend several spinal segments in Lissauer's tract and the dorsal column and regulate motor activity. Anterograde tracing demonstrated direct multisegmental projections of the sacral dorsal root 4 (S4) afferent collaterals in Lissauer's tract and in the dorsal column. Subsets of the traced S4 afferent collaterals expressed transient receptor potential vanilloid 1 (TRPV1), which transduces a nociceptive response to capsaicin. Electrophysiological data revealed that S4 dorsal root stimulation could evoke regular rhythmic bursting activity, and our data suggested that capsaicin-sensitive collaterals contribute to CPG activation across multiple segments. Capsaicin's effect on S4-evoked locomotor activity was potent until the lumbar 5 (L5) segments, and diminished in rostral segments. Using calcium imaging we found elevated calcium transients within Lissauer's tract and dorsal column at L5 segments when compared to the calcium transients only within the dorsal column at the lumbar 2 (L2) segments, which were desensitized by capsaicin. We conclude that lumbar locomotor networks in the neonatal mouse spinal cord are targets for modulation by direct multisegmental nSCA, subsets of which express TRPV1 in Lissauer's tract and the dorsal column. J. Comp. Neurol. 521:2870-2887, 2013. © 2013 Wiley Periodicals, Inc.

Funding information:
  • NHLBI NIH HHS - U54HL108460(United States)

Diverse neuronal lineages make stereotyped contributions to the Drosophila locomotor control center, the central complex.

  • Yang JS
  • J. Comp. Neurol.
  • 2013 Aug 15

Literature context:


Abstract:

The Drosophila central brain develops from a fixed number of neuroblasts. Each neuroblast makes a clone of neurons that exhibit common trajectories. Here we identified 15 distinct clones that carry larval-born neurons innervating the Drosophila central complex (CX), which consists of four midline structures including the protocerebral bridge (PB), fan-shaped body (FB), ellipsoid body (EB), and noduli (NO). Clonal analysis revealed that the small-field CX neurons, which establish intricate projections across different CX substructures, exist in four isomorphic groups that respectively derive from four complex posterior asense-negative lineages. In terms of the region-characteristic large-field CX neurons, we found that two lineages make PB neurons, 10 lineages produce FB neurons, three lineages generate EB neurons, and two lineages yield NO neurons. The diverse FB developmental origins reflect the discrete input pathways for different FB subcompartments. Clonal analysis enlightens both development and anatomy of the insect locomotor control center.

Funding information:
  • NIAID NIH HHS - T32 AI089704(United States)

Basal bodies exhibit polarized positioning in zebrafish cone photoreceptors.

  • Ramsey M
  • J. Comp. Neurol.
  • 2013 Jun 1

Literature context:


Abstract:

The asymmetric positioning of basal bodies, and therefore cilia, is often critical for proper cilia function. This planar polarity is critical for motile cilia function but has not been extensively investigated for nonmotile cilia or for sensory cilia such as vertebrate photoreceptors. Zebrafish photoreceptors form an organized mosaic ideal for investigating cilia positioning. We report that, in the adult retina, the basal bodies of red-, green-, and blue-sensitive cone photoreceptors localized asymmetrically on the cell edge nearest the optic nerve. In contrast, no patterning was seen in the basal bodies of ultraviolet-sensitive cones or in rod photoreceptors. The asymmetric localization of basal bodies was consistent in all regions of the adult retina. Basal body patterning was unaffected in the cones of the XOPS-mCFP transgenic line, which lacks rod photoreceptors. Finally, the adult pattern was not seen in 7-days-postfertilization (dpf) larvae; basal bodies were randomly distributed in all the photoreceptor subtypes. These results establish the asymmetrical localization of basal bodies in red-, green-, and blue-sensitive cones in adult zebrafish retinas but not in larvae. This pattern suggests an active cellular mechanism regulated the positioning of basal bodies after the transition to the adult mosaic and that rods do not seem to be necessary for the patterning of cone basal bodies.

Regional astrogliosis in the mouse hypothalamus in response to obesity.

  • Buckman LB
  • J. Comp. Neurol.
  • 2013 Apr 15

Literature context:


Abstract:

Obesity is associated with chronic low-grade inflammation in peripheral tissues, which contributes to the development of comorbidities such as insulin resistance and cardiovascular disease. While less extensively characterized, obesity also promotes inflammation in the central nervous system (CNS) and the consequences of this inflammation for CNS function are only beginning to be examined. In response to CNS insults such as inflammation, astrocytes undergo a process of hypertrophy and hyperplasia known as reactive astrogliosis. We used immunohistochemistry to examine the differential distribution of the astrocyte marker glial-fibrillary acidic protein (GFAP) in the brains of diet-induced or genetically obese mice compared with their respective lean controls to determine whether different nuclei of the hypothalamus showed comparable astrogliosis in response to obesity. The areas that showed the highest differential GFAP immunoreactivity between lean and obese animals include the medial preoptic, paraventricular, and dorsomedial nuclei. Comparatively, little astrogliosis was seen in the ventromedial nucleus, lateral hypothalamus, or anterior hypothalamic area. In obese animals high levels of GFAP immunoreactivity were often associated with the microvasculature. There were no differences in the differential distribution of GFAP staining between obese animals and their lean controls in the diet-induced compared with the genetic model of obesity. The exact cause(s) of the astrogliosis in obesity is not known. The finding that obesity causes a distinct pattern of elevated GFAP immunoreactivity associated with microvessels suggests that the astrogliosis may be occurring as a response to changes at the blood-brain barrier and/or in the peripheral circulation.

Funding information:
  • Wellcome Trust - (United Kingdom)

The interfascicular trigeminal nucleus: a precerebellar nucleus in the mouse defined by retrograde neuronal tracing and genetic fate mapping.

  • Fu Y
  • J. Comp. Neurol.
  • 2013 Feb 15

Literature context:


Abstract:

We have found a previously unreported precerebellar nucleus located among the emerging fibers of the motor root of the trigeminal nerve in the mouse, which we have called the interfascicular trigeminal nucleus (IF5). This nucleus had previously been named the tensor tympani part of the motor trigeminal nucleus (5TT) in rodent brain atlases, because it was thought to be a subset of small motor neurons of the motor trigeminal nucleus innervating the tensor tympani muscle. However, following injection of retrograde tracer in the cerebellum, the labeled neurons in IF5 were found to be choline acetyltransferase (ChAT) negative, indicating that they are not motor neurons. The cells of IF5 are strongly labeled in mice from Wnt1Cre and Atoh1 CreER lineage fate mapping, in common with the major precerebellar nuclei that arise from the rhombic lip and that issue mossy fibers. Analysis of sections from mouse Hoxa3, Hoxb1, and Egr2 Cre labeled lineages shows that the neurons of IF5 arise from rhombomeres caudal to rhombomere 4, most likely from rhombomeres 6-8. We conclude that IF5 is a significant precerebellar nucleus in the mouse that shares developmental gene expression characteristics with mossy fiber precerebellar nuclei that arise from the caudal rhombic lip.

Funding information:
  • Wellcome Trust - 098051(United Kingdom)

Role of EphA/ephrin--a signaling in the development of topographic maps in mouse corticothalamic projections.

  • Torii M
  • J. Comp. Neurol.
  • 2013 Feb 15

Literature context:


Abstract:

Corticothalamic (CT) feedback outnumbers thalamocortical projections and regulates sensory information processing at the level of the thalamus. It is well established that EphA7, a member of EphA receptor family, is involved in the topographic mapping of CT projections. The aim of the present study was to dissect the precise impact of EphA7 on each step of CT growth. We used in utero electroporation-mediated EphA7 overexpression in developing somatosensory CT axons to dissect EphA7/ephrin-A-dependent mechanisms involved in regulating both initial targeting and postnatal growth of the CT projections. Our data revealed that topographic maps of cortical afferents in the ventrobasal complex and medial part of the posterior complex in the thalamus become discernible shortly after birth and are fully established by the second postnatal week. This process starts with the direct ingrowth of the CT axons to the designated areas within target thalamic nuclei and by progressive increase of axonal processes in the terminal zones. Large-scale overproduction and elimination of exuberant widespread axonal branches outside the target zone was not observed. Each developmental event was coordinated by spatially and temporally different responsiveness of CT axons to the ephrin-A gradient in thalamic nuclei, as well as by the matching levels of EphA7 in CT axons and ephrin-As in thalamic nuclei. These results support the concept that the topographic connections between the maps in the cerebral cortex and corresponding thalamic nuclei are genetically prespecified to a large extent, and established by precise spatiotemporal molecular mechanisms that involve the Eph family of genes.

Funding information:
  • NHGRI NIH HHS - HG006464(United States)

Dynamics of olfactory and hippocampal neurogenesis in adult sheep.

  • Brus M
  • J. Comp. Neurol.
  • 2013 Jan 1

Literature context:


Abstract:

Although adult neurogenesis has been conserved in higher vertebrates such as primates and humans, timing of generation, migration, and differentiation of new neurons appears to differ from that in rodents. Sheep could represent an alternative model to studying neurogenesis in primates because they possess a brain as large as a macaque monkey and have a similar life span. By using a marker of cell division, bromodeoxyuridine (BrdU), in combination with several markers, the maturation time of newborn cells in the dentate gyrus (DG) and the main olfactory bulb (MOB) was determined in sheep. In addition, to establish the origin of adult-born neurons in the MOB, an adeno-associated virus that infects neural cells in the ovine brain was injected into the subventricular zone (SVZ). A migratory stream was indicated from the SVZ up to the MOB, consisting of neuroblasts that formed chain-like structures. Results also showed a long neuronal maturation time in both the DG and the MOB, similar to that in primates. The first new neurons were observed at 1 month in the DG and at 3 months in the MOB after BrdU injections. Thus, maturation of adult-born cells in both the DG and the MOB is much longer than that in rodents and resembles that in nonhuman primates. This study points out the importance of studying the features of adult neurogenesis in models other than rodents, especially for translational research for human cellular therapy.

Funding information:
  • NIMH NIH HHS - R21 MH083614(United States)

Organization of antennal lobe-associated neurons in adult Drosophila melanogaster brain.

  • Tanaka NK
  • J. Comp. Neurol.
  • 2012 Dec 15

Literature context:


Abstract:

The primary olfactory centers of both vertebrates and insects are characterized by glomerular structure. Each glomerulus receives sensory input from a specific type of olfactory sensory neurons, creating a topographic map of the odor quality. The primary olfactory center is also innervated by various types of neurons such as local neurons, output projection neurons (PNs), and centrifugal neurons from higher brain regions. Although recent studies have revealed how olfactory sensory input is conveyed to each glomerulus, it still remains unclear how the information is integrated and conveyed to other brain areas. By using the GAL4 enhancer-trap system, we conducted a systematic mapping of the neurons associated with the primary olfactory center of Drosophila, the antennal lobe (AL). We identified in total 29 types of neurons, among which 13 are newly identified in the present study. Analyses of arborizations of these neurons in the AL revealed how glomeruli are linked with each other, how different PNs link these glomeruli with multiple secondary sites, and how these secondary sites are organized by the projections of the AL-associated neurons.

Funding information:
  • European Research Council - 293681(International)
  • NIMH NIH HHS - MH078135(United States)

Coordinate development of skin cells and cutaneous sensory axons in zebrafish.

  • O'Brien GS
  • J. Comp. Neurol.
  • 2012 Mar 1

Literature context:


Abstract:

Peripheral sensory axons innervate the epidermis early in embryogenesis to detect touch stimuli. To characterize the time course of cutaneous innervation and the nature of interactions between sensory axons and skin cells at early developmental stages, we conducted a detailed analysis of cutaneous innervation in the head, trunk, and tail of zebrafish embryos and larvae from 18 to 78 hours postfertilization. This analysis combined live imaging of fish expressing transgenes that highlight sensory neurons and skin cells, transmission electron microscopy (TEM), and serial scanning electron microscopy (sSEM). In zebrafish, the skin initially consists of two epithelial layers, and all of the axons in the first wave of innervation are free endings. Maturation of the epithelium coincides with, but does not depend on, its innervation by peripheral sensory axons. We found that peripheral axons initially arborize between the two epithelial skin layers, but not within the basal lamina, as occurs in other organisms. Strikingly, as development proceeds, axons become tightly enveloped within basal keratinocytes, an arrangement suggesting that keratinocytes may serve structural or functional roles, akin to Schwann cells, in somatosensation mediated by these sensory neurons.

Funding information:
  • NICHD NIH HHS - T32 HD040128(United States)

Characterization of last-order premotor interneurons by transneuronal tracing with rabies virus in the neonatal mouse spinal cord.

  • Coulon P
  • J. Comp. Neurol.
  • 2011 Dec 1

Literature context:


Abstract:

We characterized the interneurons involved in the control of ankle extensor (triceps surae [TS] muscles) motoneurons (MNs) in the lumbar enlargement of mouse neonates by retrograde transneuronal tracing using rabies virus (RV). Examination of the kinetics of retrograde transneuronal transfer at sequential intervals post inoculation enabled us to determine the time window during which only the first-order interneurons, i.e., interneurons likely monosynaptically connected to MNs (last-order interneurons [loINs]) were RV-infected. The infection of the network resulted exclusively from a retrograde transport of RV along the motor pathway. About 80% of the loINs were observed ipsilaterally to the injection. They were distributed all along the lumbar enlargement, but the majority was observed in L4 and L5 segments where TS MNs were localized. Most loINs were distributed in laminae V-VII, whereas the most superficial laminae were devoid of RV infection. Contralaterally, commissural loINs were found essentially in lamina VIII of all lumbar segments. Groups of loINs were characterized by their chemical phenotypes using dual immunolabeling. Glycinergic neurons connected to TS MNs represented 50% of loINs ipsilaterally and 10% contralaterally. As expected, the ipsilateral glycinergic loINs included Renshaw cells, the most ventral neurons expressing calbindin. We also demonstrated a direct connection between a group of cholinergic interneurons observed ipsilaterally in L3 and the rostral part of L4, and TS MNs. To conclude, transneuronal tracing with RV, combined with an immunohistochemical detection of neuronal determinants, allows a very specific mapping of motor networks involved in the control of single muscles.

Funding information:
  • NLM NIH HHS - R01 LM06910(United States)

Ontogeny of cone photoreceptor mosaics in zebrafish.

  • Allison WT
  • J. Comp. Neurol.
  • 2010 Oct 15

Literature context:


Abstract:

Cone photoreceptors in fish are typically arranged into a precise, reiterated pattern known as a "cone mosaic." Cone mosaic patterns can vary in different fish species and in response to changes in habitat, yet their function and the mechanisms of their development remain speculative. Zebrafish (Danio rerio) have four cone subtypes arranged into precise rows in the adult retina. Here we describe larval zebrafish cone patterns and investigate a previously unrecognized transition between larval and adult cone mosaic patterns. Cone positions were determined in transgenic zebrafish expressing green fluorescent protein (GFP) in their UV-sensitive cones, by the use of multiplex in situ hybridization labelling of various cone opsins. We developed a "mosaic metric" statistical tool to measure local cone order. We found that ratios of the various cone subtypes in larval and adult zebrafish were statistically different. The cone photoreceptors in larvae form a regular heterotypic mosaic array; i.e., the position of any one cone spectral subtype relative to the other cone subtypes is statistically different from random. However, the cone spectral subtypes in larval zebrafish are not arranged in continuous rows as in the adult. We used cell birth dating to show that the larval cone mosaic pattern remains as a distinct region within the adult retina and does not reorganize into the adult row pattern. In addition, the abundance of cone subtypes relative to other subtypes is different in this larval remnant compared with that of larvae or canonical adult zebrafish retina. These observations provide baseline data for understanding the development of cone mosaics via comparative analysis of larval and adult cone development in a model species.

Funding information:
  • NCI NIH HHS - R33 CA081665-04(United States)

Neural architecture of the primary gustatory center of Drosophila melanogaster visualized with GAL4 and LexA enhancer-trap systems.

  • Miyazaki T
  • J. Comp. Neurol.
  • 2010 Oct 15

Literature context:


Abstract:

Gustatory information is essential for animals to select edible foods and avoid poisons. Whereas mammals detect tastants with their taste receptor cells, which convey gustatory signals to the brain indirectly via the taste sensory neurons, insect gustatory receptor neurons (GRNs) send their axons directly to the primary gustatory center in the suboesophageal ganglion (SOG). In spite of this relatively simple architecture, the precise structure of the insect primary gustatory center has not been revealed in enough detail. To obtain comprehensive anatomical knowledge about this brain area, we screened the Drosophila melanogaster GAL4 enhancer-trap strains that visualize specific subsets of the gustatory neurons as well as putative mechanosensory neurons associated with the taste pegs. Terminals of these neurons form three branches in the SOG. To map the positions of their arborization areas precisely, we screened newly established LexA::VP16 enhancer-trap strains and obtained a driver line that labels a large subset of peripheral sensory neurons. By double-labeling specific and landmark neurons with GAL4 and LexA strains, we were able to distinguish 11 zones in the primary gustatory center, among which 5 zones were identified newly in this study. Arborization areas of various known GRNs on the labellum, oesophagus, and legs were also mapped in this framework. The putative mechanosensory neurons terminate exclusively in three zones of these areas, supporting the notion of segregated primary centers that are specialized for chemosensory and mechanosensory signals associated with gustatory sensation.

Funding information:
  • NCRR NIH HHS - U24RR021382(United States)
  • NEI NIH HHS - R01 EY015509-03(United States)

Molecular regulation of the developing commissural plate.

  • Moldrich RX
  • J. Comp. Neurol.
  • 2010 Sep 15

Literature context:


Abstract:

Coordinated transfer of information between the brain hemispheres is essential for function and occurs via three axonal commissures in the telencephalon: the corpus callosum (CC), hippocampal commissure (HC), and anterior commissure (AC). Commissural malformations occur in over 50 human congenital syndromes causing mild to severe cognitive impairment. Disruption of multiple commissures in some syndromes suggests that common mechanisms may underpin their development. Diffusion tensor magnetic resonance imaging revealed that forebrain commissures crossed the midline in a highly specific manner within an oblique plane of tissue, referred to as the commissural plate. This specific anatomical positioning suggests that correct patterning of the commissural plate may influence forebrain commissure formation. No analysis of the molecular specification of the commissural plate has been performed in any species; therefore, we utilized specific transcription factor markers to delineate the commissural plate and identify its various subdomains. We found that the mouse commissural plate consists of four domains and tested the hypothesis that disruption of these domains might affect commissure formation. Disruption of the dorsal domains occurred in strains with commissural defects such as Emx2 and Nfia knockout mice but commissural plate patterning was normal in other acallosal strains such as Satb2(-/-). Finally, we demonstrate an essential role for the morphogen Fgf8 in establishing the commissural plate at later developmental stages. The results demonstrate that correct patterning of the commissural plate is an important mechanism in forebrain commissure formation.

Funding information:
  • NIBIB NIH HHS - 1 R01 EB005034(United States)

Structure of the adult central complex in Drosophila: organization of distinct neuronal subsets.

  • Young JM
  • J. Comp. Neurol.
  • 2010 May 1

Literature context:


Abstract:

The central complex (CX) is a defined set of neuropils located on the midline of the protocerebrum in several arthropods and has been implicated in a number of behaviors. To investigate the function of the CX further it is imperative to know the neuroarchitecture of this structure and to ensure all known neuron types conform to a common nomenclature system. Several types of CX neuron have been identified but it is not known if these exist singly or as components of isomorphic sets. We used an enhancer trap approach to study the adult structure, connectivity, and polarity of CX neurons in Drosophila. We observed several isomorphic sets of small-field neurons including pontine and fb-eb neurons, and also isomorphic sets of large-field neurons including R neurons and F neurons. We found that several types of large-field F neurons existed in isomorphic sets of approximately eight (four per hemisphere) and found evidence for small-field neuron types existing as isomorphic sets of 16. Small-field neurons were observed in clearly organized layers. This study provides a novel insight into CX structure and connectivity and provides a set of characterized enhancer trap lines that will be valuable for future study.

Bilateral whisker trimming during early postnatal life impairs dendritic spine development in the mouse somatosensory barrel cortex.

  • Briner A
  • J. Comp. Neurol.
  • 2010 May 15

Literature context:


Abstract:

The rodent somatosensory barrel cortex is an ideal model for studying the impact of sensory experience on developing brain circuitry. To examine whether and how interference with sensory perception in the early postnatal period can affect the development of synaptic networks in this system, we took advantage of a transgenic mouse strain expressing the yellow fluorescent protein in layer 5B pyramidal neurons of the somatosensory cortex. By using ex vivo confocal imaging, we first demonstrate a cortical-layer-specific increase in the number of dendritic spines during postnatal development on apical dendritic shafts of these cells extending up to cortical layer 1. Next, by performing bilateral whisker trimming at distinct developmental stages, we show that disruption of sensory perception before postnatal day 20 impairs dendritic spine development in apical dendritic segments within layers 1 and 2/3 but not in layer 4. The whisker trimming-induced decrease in dendritic spine density during this period is accompanied by a highly significant decrease in dendritic spine head diameter. Finally, we also show that these whisker trimming-induced morphological alterations of dendritic spines during the early postnatal period are no longer detectable in adult animals. Altogether, these findings further emphasize the important role of sensory activity in synaptic network assembly in the developing barrel cortex. They also support an as yet unidentified structural mechanism that might contribute to the layer- and cell-type-specific physiological effects of whisker trimming during the early postnatal period.

Building the central complex in Drosophila: the generation and development of distinct neural subsets.

  • Young JM
  • J. Comp. Neurol.
  • 2010 May 1

Literature context:


Abstract:

The distinctive midline neuropil, the central complex (CX), is one of the most prominent features of the insect brain. We investigated the development of the four CX structures and several sets of CX neurons in the Drosophila brain using immunostaining for two cell adhesion molecules, DN-cadherin and Echinoid, and a set of seven enhancer trap lines. Our results showed that the CX is first identifiable in the third instar larva and that it elaborates over the first 48 hours of metamorphosis. The first identifiable structures to appear in their immature form are the protocerebral bridge and fan-shaped body, which are present in the brain of the third instar larva, followed by the noduli (from P12h), and finally the ellipsoid body (from P24h). We observed that neurons are added incrementally to the developing CX structure, with sets of small-field neurons projecting to the CX prior to the large-field neurons. The small-field neurons first project to the developing fan-shaped body, before arborizing or extending to the other structures. We found evidence to suggest that small-field neurons exist in sets of 16 and that they originate from eight common clusters of perikarya in the cortex, suggesting a common origin. We also identified a novel set of pontine neurons that connect contralateral segments in the fan-shaped body.

Prokineticin receptor 2 expression identifies migrating neuroblasts and their subventricular zone transient-amplifying progenitors in adult mice.

  • Puverel S
  • J. Comp. Neurol.
  • 2009 Jan 10

Literature context:


Abstract:

The adult subventricular zone (SVZ) contains progenitors cells, which continually give rise to new neurons that migrate along the rostral migratory stream (RMS) to the olfactory bulbs (OB). Prokineticin receptor 2 (ProKR2) is a G-protein-coupled receptor that plays an essential role in this migration process. However, the identity of the prokr2-expressing cells has not yet been clearly established. Here, we have characterized in detail the identity of the prokr2-expressing cells in the SVZ/RMS/OB pathway in adult mice. In the SVZ, accumulation of prokr2 transcripts was detected in almost all migrating neuroblasts or type A cells as well as in a large population of their precursors, the rapidly dividing type C cells. Moreover, we observed that, in dissociated SVZ cells from Mash1::GFP postnatal mice, ProKR2 protein is also present in type C and type A cells. We found that, along the RMS and in the OB, prokr2 expression was restricted to migrating type A cells and was absent in astrocytes. Finally, we observed a highly marked decrease of prokr2 expression in Mash1-/- mutant mice, suggesting that this transcription factor directly or indirectly regulates prokr2 expression. Although the expression of ProKR2 in migrating type A cells is in good agreement with the essential role played by this receptor during this migration process, its expression in a large population of their progenitors suggests an additional function for ProKR2, providing novel insights into the role of ProKR2/ProK2 signalling in adult neurogenesis.

Funding information:
  • NINDS NIH HHS - R01 NS045734(United States)

Genetic tracing of subpopulation neurons in the prethalamus of mice (Mus musculus).

  • Delaunay D
  • J. Comp. Neurol.
  • 2009 Jan 1

Literature context:


Abstract:

Genetic labeling based on the Cre/lox reporter system has allowed the creation of fate maps for progenitor cells and their offspring. In the diencephalon, pools of progenitors express the plp transcripts in the zona limitans intrathalamica (ZLI), the basal plate of the diencephalon (bpD), and the posterior part of the hypothalamus. We used plp-Cre transgenics crossed with either Rosa26-lox-lacZ (R26R) or actin-lox gfp (Z/EG) reporter mice to investigate the progeny of plp-expressing ventricular cells in the diencephalon. We describe the subpopulations of prethalamic neurons derived from plp-activated progenitors, their possible migratory routes as development proceeds, and their final positional identity. Neurons derived from plp-expressing progenitors issued from the ZLI contribute to GABAergic cells in the zona incerta, the subgeniculate nucleus, the ventral lateral geniculate, and the intergeniculate leaflet. Plp(+) progenitors in the bpD and posterior hypothalamus appear to generate glutamatergic neurons in the subthalamic nucleus and GABAergic neurons in the mammillary and retromammillary tegmentum derivatives. In all these nuclei the contribution of plp(+) progenitors is only partial, illustrating the heterogeneity of origin of neurons in prethalamic and caudal hypothalamic nuclei.

Type 1 corticotropin-releasing factor receptor expression reported in BAC transgenic mice: implications for reconciling ligand-receptor mismatch in the central corticotropin-releasing factor system.

  • Justice NJ
  • J. Comp. Neurol.
  • 2008 Dec 1

Literature context:


Abstract:

In addition to its established role in initiating the endocrine arm of the stress response, corticotropin-releasing factor (CRF) can act in the brain to modulate neural pathways that effect coordinated physiological and behavioral adjustments to stress. Although CRF is expressed in a set of interconnected limbic and autonomic cell groups implicated as primary sites of stress-related peptide action, most of these are lacking or impoverished in CRF receptor (CRFR) expression. Understanding the distribution of functional receptor expression has been hindered by the low resolution of ligand binding approaches and the lack of specific antisera, which have supported immunolocalizations at odds with analyses at the mRNA level. We have generated a transgenic mouse that shows expression of the principal, or type 1, CRFR (CRFR1). This mouse expresses GFP in a cellular distribution that largely mimics that of CRFR1 mRNA and is extensively colocalized with it in individual neurons. GFP-labeled cells display indices of activation (Fos induction) in response to central CRF injection. At the cellular level, GFP labeling marks somatic and proximal dendritic morphology with high resolution and is also localized to axonal projections of at least some labeled cell groups. This includes a presence in synaptic inputs to central autonomic structures such as the central amygdalar nucleus, which is implicated as a stress-related site of CRF action, but lacks cellular CRFR1 expression. These findings validate a new tool for pursuing the role of central CRFR signaling in stress adaptation and suggest means by which the pervasive ligand-receptor mismatch in this system may be reconciled.

Distinct molecular pathways for development of telencephalic interneuron subtypes revealed through analysis of Lhx6 mutants.

  • Zhao Y
  • J. Comp. Neurol.
  • 2008 Sep 1

Literature context:


Abstract:

Here we analyze the role of the Lhx6 lim-homeobox transcription factor in regulating the development of subsets of neocortical, hippocampal, and striatal interneurons. An Lhx6 loss-of-function allele, which expresses placental alkaline phosphatase (PLAP), allowed analysis of the development and fate of Lhx6-expressing interneurons in mice lacking this homeobox transcription factor. There are Lhx6+;Dlx+ and Lhx6-;Dlx+ subtypes of tangentially migrating interneurons. Most interneurons in Lhx6(PLAP/PLAP) mutants migrate to the cortex, although less efficiently, and exhibit defects in populating the marginal zone and superficial parts of the neocortical plate. By contrast, migration to superficial parts of the hippocampus is not seriously affected. Furthermore, whereas parvalbumin+ and somatostatin+ interneurons do not differentiate, NPY+ interneurons are present; we suggest that these NPY+ interneurons are derived from the Lhx6-;Dlx+ subtype. Striatal interneurons show deficits distinct from pallial interneurons, including a reduction in the NPY+ subtype. We provide evidence that Lhx6 mediates these effects through promoting expression of receptors that regulate interneuron migration (ErbB4, CXCR4, and CXCR7), and through promoting the expression of transcription factors either known (Arx) or implicated (bMaf, Cux2, and NPAS1) in controlling interneuron development.

Fate mapping Nkx2.1-lineage cells in the mouse telencephalon.

  • Xu Q
  • J. Comp. Neurol.
  • 2008 Jan 1

Literature context:


Abstract:

The homeodomain transcription factor Nkx2.1 is expressed in the pallidal (subcortical) telencephalon, including the medial ganglionic eminence (MGE) and preoptic area. Studies have shown that Nkx2.1 is required for normal patterning of the MGE and for the specification of the parvalbumin (PV)- and somatostatin (SST)-expressing cortical interneurons. To define the contribution of Nkx2.1 lineages to neurons in the mature telencephalon, we have generated transgenic mice carrying the genomic integration of a modified bacterial artificial chromosome (BAC) in which the second exon of Nkx2.1 is replaced by the Cre recombinase. Analysis of these mice has found that they express the Cre recombinase and Cre reporters within Nkx2.1-expressing domains of the brain, thyroid, pituitary, and lung. Telencephalic expression of reporters begins at about embryonic day 10.5. Expression both of Cre and of recombination-based Cre reporters is weaker within the dorsalmost region of the MGE than in other Nkx2.1-expressing regions. In this paper, we present fate-mapping data on Nkx2.1-lineage neurons throughout the telencephalon, including the cerebral cortex, amygdala, olfactory bulb, striatum, globus pallidus, septum, and nucleus basalis.

Funding information:
  • NINDS NIH HHS - R01 NS059600(United States)

Chemokine receptor expression by neural progenitor cells in neurogenic regions of mouse brain.

  • Tran PB
  • J. Comp. Neurol.
  • 2007 Feb 20

Literature context:


Abstract:

We previously demonstrated that chemokine receptors are expressed by neural progenitors grown as cultured neurospheres. To examine the significance of these findings for neural progenitor function in vivo, we investigated whether chemokine receptors were expressed by cells having the characteristics of neural progenitors in neurogenic regions of the postnatal brain. Using in situ hybridization we demonstrated the expression of CCR1, CCR2, CCR5, CXCR3, and CXCR4 chemokine receptors by cells in the dentate gyrus (DG), subventricular zone of the lateral ventricle, and olfactory bulb. The pattern of expression for all of these receptors was similar, including regions where neural progenitors normally reside. In addition, we attempted to colocalize chemokine receptors with markers for neural progenitors. In order to do this we used nestin-EGFP and TLX-LacZ transgenic mice, as well as labeling for Ki67, a marker for dividing cells. In all three areas of the brain we demonstrated colocalization of chemokine receptors with these three markers in populations of cells. Expression of chemokine receptors by neural progenitors was further confirmed using CXCR4-EGFP BAC transgenic mice. Expression of CXCR4 in the DG included cells that expressed nestin and GFAP as well as cells that appeared to be immature granule neurons expressing PSA-NCAM, calretinin, and Prox-1. CXCR4-expressing cells in the DG were found in close proximity to immature granule neurons that expressed the chemokine SDF-1/CXCL12. Cells expressing CXCR4 frequently coexpressed CCR2 receptors. These data support the hypothesis that chemokine receptors are important in regulating the migration of progenitor cells in postnatal brain.

Funding information:
  • Biotechnology and Biological Sciences Research Council - BB/H024808/1(United Kingdom)

Comprehensive classification of the auditory sensory projections in the brain of the fruit fly Drosophila melanogaster.

  • Kamikouchi A
  • J. Comp. Neurol.
  • 2006 Nov 20

Literature context:


Abstract:

We established a comprehensive projection map of the auditory receptor cells (Johnston's organ neurons: JONs) from the antennae to the primary auditory center of the Drosophila brain. We found 477 +/- 24 cell bodies of JONs, which are arranged like a "bottomless bowl" within the auditory organ. The target of the JONs in the brain comprises five spatially segregated zones, each of which is contributed by bundles of JON axons that gradually branch out from the antennal nerve. Four zones are confined in the antennal mechanosensory and motor center, whereas one zone further extends over parts of the ventrolateral protocerebrum and the subesophageal ganglion. Single-cell labeling with the FLP-out technique revealed that most JONs innervate only a single zone, indicating that JONs can be categorized into five groups according to their target zones. Within each zone, JONs innervate various combinations of subareas. We classified these five zones into 19 subareas according to the branching patterns and terminal distributions of single JON axons. The groups of JONs that innervate particular zones or subareas of the primary auditory center have their cell bodies in characteristic locations of the Johnston's organ in the antenna, e.g., in concentric rings or in paired clusters. Such structural organization suggests that each JON group, and hence each zone of the primary auditory center, might sense different aspects of sensory signals.

Funding information:
  • NINDS NIH HHS - R01 NS 055064(United States)