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CGRP (Calcitonin Gene Related Peptide) Antibody

RRID:AB_572217

Antibody ID

AB_572217

Target Antigen

rat alpha-CGRP See NCBI gene bullfrog, cat, dog, hamster, human, mouse, mudpuppy, ovine (sheep), pig, platypus, ram (sheep), rat

Proper Citation

(ImmunoStar Cat# 24112, RRID:AB_572217)

Clonality

polyclonal antibody

Comments

Manufacturer Applications: Immunohistochemistry, Immunocytochemistry, Immunofluoresence; Note, The CGRP Antibody was raised to rat alpha-CGRP coupled to bovine thyroglobulin with glutaraldehyde. The antibody has a proven fluorescein staining at a 1/100-1/200 dilution and a strong Biotin-Streptadvidin/HRP staining at a 1/2000-1/4000 dilution in rat amygdala, and spinal cord. The specificity of the antiserum was evaluated by soluble pre-adsorption with the peptides in question at a final concentration of 10-5M. CGRP immunolabeling was completely abolished by pre-adsorption with rat α -CGRP and partially eliminated by pre-adsorption with rat

Host Organism

rabbit

Vendor

ImmunoStar Go To Vendor

Opposing expression gradients of calcitonin-related polypeptide alpha (Calca/Cgrpα) and tyrosine hydroxylase (Th) in type II afferent neurons of the mouse cochlea.

  • Wu JS
  • J. Comp. Neurol.
  • 2018 Feb 15

Literature context:


Abstract:

Type II spiral ganglion neurons (SGNs) are small caliber, unmyelinated afferents that extend dendritic arbors hundreds of microns along the cochlear spiral, contacting many outer hair cells (OHCs). Despite these many contacts, type II afferents are insensitive to sound and only weakly depolarized by glutamate release from OHCs. Recent studies suggest that type II afferents may be cochlear nociceptors, and can be excited by ATP released during tissue damage, by analogy to somatic pain-sensing C-fibers. The present work compares the expression patterns among cochlear type II afferents of two genes found in C-fibers: calcitonin-related polypeptide alpha (Calca/Cgrpα), specific to pain-sensing C-fibers, and tyrosine hydroxylase (Th), specific to low-threshold mechanoreceptive C-fibers, which was shown previously to be a selective biomarker of type II versus type I cochlear afferents (Vyas et al., ). Whole-mount cochlear preparations from 3-week- to 2-month-old CGRPα-EGFP (GENSAT) mice showed expression of Cgrpα in a subset of SGNs with type II-like peripheral dendrites extending beneath OHCs. Double labeling with other molecular markers confirmed that the labeled SGNs were neither type I SGNs nor olivocochlear efferents. Cgrpα starts to express in type II SGNs before hearing onset, but the expression level declines in the adult. The expression patterns of Cgrpα and Th formed opposing gradients, with Th being preferentially expressed in apical and Cgrpα in basal type II afferent neurons, indicating heterogeneity among type II afferent neurons. The expression of Th and Cgrpα was not mutually exclusive and co-expression could be observed, most abundantly in the middle cochlear turn.

Funding information:
  • NIDCD NIH HHS - R01 DC006476()
  • NIDCD NIH HHS - R01 DC011741()
  • NIDCD NIH HHS - R01 DC012957()

Identification of Two Classes of Somatosensory Neurons That Display Resistance to Retrograde Infection by Rabies Virus.

  • Albisetti GW
  • J. Neurosci.
  • 2017 Oct 25

Literature context:


Abstract:

Glycoprotein-deleted rabies virus-mediated monosynaptic tracing has become a standard method for neuronal circuit mapping, and is applied to virtually all parts of the rodent nervous system, including the spinal cord and primary sensory neurons. Here we identified two classes of unmyelinated sensory neurons (nonpeptidergic and C-fiber low-threshold mechanoreceptor neurons) resistant to direct and trans-synaptic infection from the spinal cord with rabies viruses that carry glycoproteins in their envelopes and that are routinely used for infection of CNS neurons (SAD-G and N2C-G). However, the same neurons were susceptible to infection with EnvA-pseudotyped rabies virus in tumor virus A receptor transgenic mice, indicating that resistance to retrograde infection was due to impaired virus adsorption rather than to deficits in subsequent steps of infection. These results demonstrate an important limitation of rabies virus-based retrograde tracing of sensory neurons in adult mice, and may help to better understand the molecular machinery required for rabies virus spread in the nervous system. In this study, mice of both sexes were used.SIGNIFICANCE STATEMENT To understand the neuronal bases of behavior, it is important to identify the underlying neural circuitry. Rabies virus-based monosynaptic tracing has been used to identify neuronal circuits in various parts of the nervous system. This has included connections between peripheral sensory neurons and their spinal targets. These connections form the first synapse in the somatosensory pathway. Here we demonstrate that two classes of unmyelinated sensory neurons, which account for >40% of dorsal root ganglia neurons, display resistance to rabies infection. Our results are therefore critical for interpreting monosynaptic rabies-based tracing in the sensory system. In addition, identification of rabies-resistant neurons might provide a means for future studies addressing rabies pathobiology.

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

  • Olson W
  • Elife
  • 2017 Oct 12

Literature context:


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()

Spinal nociceptive circuit analysis with recombinant adeno-associated viruses: the impact of serotypes and promoters.

  • Haenraets K
  • J. Neurochem.
  • 2017 Sep 12

Literature context:


Abstract:

Recombinant adeno-associated virus (rAAV) vector-mediated gene transfer into genetically defined neuron subtypes has become a powerful tool to study the neuroanatomy of neuronal circuits in the brain and to unravel their functions. More recently, this methodology has also become popular for the analysis of spinal cord circuits. To date, a variety of naturally occurring AAV serotypes and genetically modified capsid variants are available but transduction efficiency in spinal neurons, target selectivity, and the ability for retrograde tracing are only incompletely characterized. Here, we have compared the transduction efficiency of seven commonly used AAV serotypes after intraspinal injection. We specifically analyzed local transduction of different types of dorsal horn neurons, and retrograde transduction of dorsal root ganglia (DRG) neurons and of neurons in the rostral ventromedial medulla (RVM) and the somatosensory cortex (S1). Our results show that most of the tested rAAV vectors have similar transduction efficiency in spinal neurons. All serotypes analyzed were also able to transduce DRG neurons and descending RVM and S1 neurons via their spinal axon terminals. When comparing the commonly used rAAV serotypes to the recently developed serotype 2 capsid variant rAAV2retro, a > 20-fold increase in transduction efficiency of descending supraspinal neurons was observed. Conversely, transgene expression in retrogradely transduced neurons was strongly reduced when the human synapsin 1 (hSyn1) promoter was used instead of the strong ubiquitous hybrid cytomegalovirus enhancer/chicken β-actin promoter (CAG) or cytomegalovirus (CMV) promoter fragments. We conclude that the use of AAV2retro greatly increases transduction of neurons connected to the spinal cord via their axon terminals, while the hSyn1 promoter can be used to minimize transgene expression in retrogradely connected neurons of the DRG or brainstem. Cover Image for this issue: doi. 10.1111/jnc.13813.

Select noxious stimuli induce changes on corneal nerve morphology.

  • Hegarty DM
  • J. Comp. Neurol.
  • 2017 Jun 1

Literature context:


Abstract:

The surface of the cornea contains the highest density of nociceptive nerves of any tissue in the body. These nerves are responsive to a variety of modalities of noxious stimuli and can signal pain even when activated by low threshold stimulation. Injury of corneal nerves can lead to altered nerve morphology, including neuropathic changes which can be associated with chronic pain. Emerging technologies that allow imaging of corneal nerves in vivo are spawning questions regarding the relationship between corneal nerve density, morphology, and function. We tested whether noxious stimulation of the corneal surface can alter nerve morphology and neurochemistry. We used concentrations of menthol, capsaicin, and hypertonic saline that evoked comparable levels of nocifensive eye wipe behaviors when applied to the ocular surface of an awake rat. Animals were sacrificed and corneal nerves were examined using immunocytochemistry and three-dimensional volumetric analyses. We found that menthol and capsaicin both caused a significant reduction in corneal nerve density as detected with β-tubulin immunoreactivity 2 hr after stimulation. Hypertonic saline did not reduce nerve density, but did cause qualitative changes in nerves including enlarged varicosities that were also seen following capsaicin and menthol stimulation. All three types of noxious stimuli caused a depletion of CGRP from corneal nerves, indicating that all modalities of noxious stimuli evoked peptide release. Our findings suggest that studies aimed at understanding the relationship between corneal nerve morphology and chronic disease may also need to consider the effects of acute stimulation on corneal nerve morphology.

Mediation of Movement-Induced Breakthrough Cancer Pain by IB4-Binding Nociceptors in Rats.

  • Havelin J
  • J. Neurosci.
  • 2017 May 17

Literature context:


Abstract:

Cancer-induced bone pain is characterized by moderate to severe ongoing pain that commonly requires the use of opiates. Even when ongoing pain is well controlled, patients can suffer breakthrough pain (BTP), episodic severe pain that "breaks through" the medication. We developed a novel model of cancer-induced BTP using female rats with mammary adenocarcinoma cells sealed within the tibia. We demonstrated previously that rats with bone cancer learn to prefer a context paired with saphenous nerve block to elicit pain relief (i.e., conditioned place preference, CPP), revealing the presence of ongoing pain. Treatment with systemic morphine abolished CPP to saphenous nerve block, demonstrating control of ongoing pain. Here, we show that pairing BTP induced by experimenter-induced movement of the tumor-bearing hindlimb with a context produces conditioned place avoidance (CPA) in rats treated with morphine to control ongoing pain, consistent with clinical observation of BTP. Preventing movement-induced afferent input by saphenous nerve block before, but not after, hindlimb movement blocked movement-induced BTP. Ablation of isolectin B4 (IB4)-binding, but not TRPV1+, sensory afferents eliminated movement-induced BTP, suggesting that input from IB4-binding fibers mediates BTP. Identification of potential molecular targets specific to this population of fibers may allow for the development of peripherally restricted analgesics that control BTP and improve quality of life in patients with skeletal metastases.SIGNIFICANCE STATEMENT We present a novel preclinical measure of movement-induced breakthrough pain (BTP) that is observed in the presence of morphine controlling ongoing pain. Blockade of sensory input before movement prevented BTP, whereas nerve block after movement failed to reverse BTP. These observations indicate that blocking peripheral sensory input may prevent BTP and targeting central sites may be required for pain relief once BTP has been initiated. Preventing sensory input from TRPV1-expressing fibers failed to alter movement-induced BTP. In contrast, preventing sensory input from isolectin B4 (IB4)-binding fibers blocked movement-induced BTP. Therefore, examining molecular targets on this population of nociceptive fibers may prove useful for developing an improved strategy for preventing BTP in cancer patients with skeletal metastases.

FGF13 Selectively Regulates Heat Nociception by Interacting with Nav1.7.

  • Yang L
  • Neuron
  • 2017 Feb 22

Literature context:


Abstract:

The current knowledge about heat nociception is mainly confined to the thermosensors, including the transient receptor potential cation channel V1 expressed in the nociceptive neurons of dorsal root ganglion (DRG). However, the loss of thermosensors only partially impairs heat nociception, suggesting the existence of undiscovered mechanisms. We found that the loss of an intracellular fibroblast growth factor (FGF), FGF13, in the mouse DRG neurons selectively abolished heat nociception. The noxious heat stimuli could not evoke the sustained action potential firing in FGF13-deficient DRG neurons. Furthermore, FGF13 interacted with the sodium channel Nav1.7 in a heat-facilitated manner. FGF13 increased Nav1.7 sodium currents and maintained the membrane localization of Nav1.7 during noxious heat stimulation, enabling the sustained firing of action potentials. Disrupting the FGF13/Nav1.7 interaction reduced the heat-evoked action potential firing and nociceptive behavior. Thus, beyond the thermosensors, the FGF13/Nav1.7 complex is essential for sustaining the transmission of noxious heat signals.

Ontogenic development of nerve fibers in human fetal livers: an immunohistochemical study using neural cell adhesion molecule (NCAM) and neuron-specific enolase (NSE).

  • Terada T
  • Histochem. Cell Biol.
  • 2015 Apr 13

Literature context:


Abstract:

The aim of the study was to investigate nerve fibers (NF) in human fetal livers. An immunohistochemical study was performed. NF were classified into portal tract innervation (PoI) and parenchymal innervation (PaI). The hilum area showed many Pol NF at 7 GW, and NF increased with gestational week (GW). Direct innervations to biliary epithelium were recognized. In large portal tracts, a few NCAM-positive mesenchymal cells were seen at 8 GW and many mesenchymal cells were noted around 12 GW. Apparent NF emerged around 15 GW, and NF increased with GW. Many NF plexuses were seen in 30-40 GW. In small portal tracts, no NF were seen in 7-10 GW. A few NCAM-positive mesenchymal cells emerged in 11 GW, and they increased thereafter. Apparent NF were seen around 20 GW and NF increased with GW. At term (40 GW), PoI NF were still immature. Ductal plate (DP) was positive for NCAM, NSE, chromogranin and synaptophysin, and direct innervations to DP were seen. The direct innervations to developing bile ducts and peribiliary glands were also seen. PaI NF were first seen at 21 GW and was consistent until 40 GW in which a few NF were seen in PaI. These observations suggest that PoI NF arise from committed portal mesenchyme. PaI NF are very immature at 40 GW. There are direct innervations to bile ducts, peribiliary glands, portal veins, hepatic arteries, and DP.

Funding information:
  • NCRR NIH HHS - P20RR016475(United States)
  • NIDA NIH HHS - R21 DA034195(United States)

Quantitative analysis of afferents expressing substance P, calcitonin gene-related peptide, isolectin B4, neurofilament 200, and Peripherin in the sensory root of the rat trigeminal ganglion.

  • Bae JY
  • J. Comp. Neurol.
  • 2015 Jan 1

Literature context:


Abstract:

Substance P (SP), calcitonin gene-related peptide (CGRP), and isolectin B4 (IB4) are widely used as markers for peripheral neurons with unmyelinated fibers, whereas neurofilament 200 (NF200), and Peripherin are used as markers for neurons with myelinated fibers, and with unmyelinated or small-caliber fibers, respectively. To study the selectivity of these markers for specific neuronal types, we analyzed their expression in neurons in the rat trigeminal ganglion by light- and electron-microscopic immunocytochemistry. Most SP-immunopositive (+), CGRP+, and IB4+ fibers were unmyelinated, but a small fraction (∼5%) were small myelinated fibers (<20 µm(2) in cross-sectional area, equivalent to <5 µm in diameter, Aδ fiber). Similarly, whereas the majority of NF200+ fibers were myelinated, a large fraction (23.9%) were unmyelinated, and whereas the majority of Peripherin+ fibers were unmyelinated and small myelinated, a significant fraction (15.5%) were large myelinated (>20 µm(2) in cross-sectional area, equivalent to >5 µm in diameter, Aβ fiber). Our findings confirm that SP, CGRP, and IB4 can be used as reliable markers for neurons with unmyelinated fibers, and question the suitability of NF200 as a marker for neurons with myelinated fibers, and of Peripherin as a marker for neurons with unmyelinated, or fine-caliber fibers.

Efficacy of anti-nerve growth factor therapy for discogenic neck pain in rats.

  • Sainoh T
  • Spine
  • 2014 Jun 1

Literature context:


Abstract:

STUDY DESIGN: Immunohistological analysis of the cervical dorsal root ganglia (DRG). OBJECTIVE: To investigate immunohistologically in rats whether intradiscal administration of anti-nerve growth factor (NGF) antibody in injured cervical intervertebral discs (IVDs) suppresses pain-related peptide expression in DRG neurons. SUMMARY OF BACKGROUND DATA: Neck pain can involve the entire neck and become chronic and intractable. Cervical disc degeneration is a primary cause of neck pain, and pain-related mediators, such as NGF, have been correlated with discogenic pain. METHODS: We examined Sprague-Dawley rats that received 10 punctures in the C5-C6 IVD, and were treated with saline (puncture group) or an anti-NGF antibody (anti-NGF group). The retrograde neurotracer Fluoro-Gold (FG) was then injected into the C5-C6 IVD. In addition, we examined a sham group that did not receive punctures (disc nonpuncture). The C2-C7 DRG were harvested 1 week after surgery and immunostained for calcitonin gene-related peptide (CGRP), a marker for peptide-containing neurons. We determined for each group the percentages of FG-labeled DRG neurons that were CGRP-immunoreactive (CGRP-ir). RESULTS: FG-labeled neurons innervating the C5-C6 IVD were found in all C2-C7 DRG examined. The percentage of FG-labeled CGRP-ir DRG neurons in the puncture group was significantly higher than that observed in the sham (P < 0.001) and anti-NGF groups (P < 0.001), but there was no significant difference between the sham and anti-NGF groups (P > 0.05). Therefore, intradiscal administration of anti-NGF antibody suppressed CGRP expression the cervical DRG. CONCLUSION: Neurons located in the C2-C7 DRG innervated the C5-C6 IVD. These findings indicate that neck pain may be derived from degenerated IVDs. Furthermore, intradiscal administration of anti-NGF antibody suppressed CGRP expression in the cervical DRG innervating the injured IVD. Therefore, inhibiting NGF upregulation in the cervical IVD may be an efficient treatment for discogenic neck pain. LEVEL OF EVIDENCE: N/A.

Funding information:
  • NEI NIH HHS - R01 EY020533(United States)
  • NIGMS NIH HHS - R01 GM088803(United States)

Modality-based organization of ascending somatosensory axons in the direct dorsal column pathway.

  • Niu J
  • J. Neurosci.
  • 2013 Nov 6

Literature context:


Abstract:

The long-standing doctrine regarding the functional organization of the direct dorsal column (DDC) pathway is the "somatotopic map" model, which suggests that somatosensory afferents are primarily organized by receptive field instead of modality. Using modality-specific genetic tracing, here we show that ascending mechanosensory and proprioceptive axons, two main types of the DDC afferents, are largely segregated into a medial-lateral pattern in the mouse dorsal column and medulla. In addition, we found that this modality-based organization is likely to be conserved in other mammalian species, including human. Furthermore, we identified key morphological differences between these two types of afferents, which explains how modality segregation is formed and why a rough "somatotopic map" was previously detected. Collectively, our results establish a new functional organization model for the mammalian direct dorsal column pathway and provide insight into how somatotopic and modality-based organization coexist in the central somatosensory pathway.

Funding information:
  • NIDDK NIH HHS - U01 DK067861(United States)

A comparison of the behavioral and anatomical outcomes in sub-acute and chronic spinal cord injury models following treatment with human mesenchymal precursor cell transplantation and recombinant decorin.

  • Hodgetts SI
  • Exp. Neurol.
  • 2013 Oct 13

Literature context:


Abstract:

This study assessed the potential of highly purified (Stro-1(+)) human mesenchymal precursor cells (hMPCs) in combination with the anti-scarring protein decorin to repair the injured spinal cord (SC). Donor hMPCs isolated from spinal cord injury (SCI) patients were transplanted into athymic rats as a suspension graft, alone or after previous treatment with, core (decorin(core)) and proteoglycan (decorin(pro)) isoforms of purified human recombinant decorin. Decorin was delivered via mini-osmotic pumps for 14 days following sub-acute (7 day) or chronic (1 month) SCI. hMPCs were delivered to the spinal cord at 3 weeks or 6 weeks after the initial injury at T9 level. Behavioral and anatomical analysis in this study showed statistically significant improvement in functional recovery, tissue sparing and cyst volume reduction following hMPC therapy. The combination of decorin infusion followed by hMPC therapy did not improve these measured outcomes over the use of cell therapy alone, in either sub-acute or chronic SCI regimes. However, decorin infusion did improve tissue sparing, reduce spinal tissue cavitation and increase transplanted cell survivability as compared to controls. Immunohistochemical analysis of spinal cord sections revealed differences in glial, neuronal and extracellular matrix molecule expression within each experimental group. hMPC transplanted spinal cords showed the increased presence of serotonergic (5-HT) and sensory (CGRP) axonal growth within and surrounding transplanted hMPCs for up to 2 months; however, no evidence of hMPC transdifferentiation into neuronal or glial phenotypes. The number of hMPCs was dramatically reduced overall, and no transplanted cells were detected at 8 weeks post-injection using lentiviral GFP labeling and human nuclear antigen antibody labeling. The presence of recombinant decorin in the cell transplantation regimes delayed in part the loss of donor cells, with small numbers remaining at 2 months after transplantation. In vitro co-culture experiments with embryonic dorsal root ganglion explants revealed the growth promoting properties of hMPCs. Decorin did not increase axonal outgrowth from that achieved by hMPCs. We provide evidence for the first time that (Stro-1(+)) hMPCs provide: i) an advantageous source of allografts for stem cell transplantation for sub-acute and chronic spinal cord therapy, and (ii) a positive host microenvironment that promotes tissue sparing/repair that subsequently improves behavioral outcomes after SCI. This was not measurably improved by recombinant decorin treatment, but does provide important information for the future development and potential use of decorin in contusive SCI therapy.

Funding information:
  • Biotechnology and Biological Sciences Research Council - BB/E006248/1(United Kingdom)
  • NIAMS NIH HHS - R01 AR049022(United States)

Forced desynchrony reveals independent contributions of suprachiasmatic oscillators to the daily plasma corticosterone rhythm in male rats.

  • Wotus C
  • PLoS ONE
  • 2013 Jul 29

Literature context:


Abstract:

The suprachiasmatic nucleus (SCN) is required for the daily rhythm of plasma glucocorticoids; however, the independent contributions from oscillators within the different subregions of the SCN to the glucocorticoid rhythm remain unclear. Here, we use genetically and neurologically intact, forced desynchronized rats to test the hypothesis that the daily rhythm of the glucocorticoid, corticosterone, is regulated by both light responsive and light-dissociated circadian oscillators in the ventrolateral (vl-) and dorsomedial (dm-) SCN, respectively. We show that when the vlSCN and dmSCN are in maximum phase misalignment, the peak of the plasma corticosterone rhythm is shifted and the amplitude reduced; whereas, the peak of the plasma adrenocorticotropic hormone (ACTH) rhythm is also reduced, the phase is dissociated from that of the corticosterone rhythm. These data support previous studies suggesting an ACTH-independent pathway contributes to the corticosterone rhythm. To determine if either SCN subregion independently regulates corticosterone through the sympathetic nervous system, we compared unilateral adrenalectomized, desynchronized rats that had undergone either transection of the thoracic splanchnic nerve or sham transection to the remaining adrenal. Splanchnicectomy reduced and phase advanced the peak of both the corticosterone and ACTH rhythms. These data suggest that both the vlSCN and dmSCN contribute to the corticosterone rhythm by both reducing plasma ACTH and differentially regulating plasma corticosterone through an ACTH- and sympathetic nervous system-independent pathway.

Funding information:
  • NHLBI NIH HHS - HL64541(United States)

IκB kinase β inhibitor downregulates pain-related neuropeptide production in the sensory neurons innervating injured lumbar intervertebral discs in the dorsal root ganglia of rats.

  • Orita S
  • Spine J
  • 2013 Mar 29

Literature context:


Abstract:

BACKGROUND CONTEXT: Nuclear factor-κB (NF-κB) is an essential gene transcriptional regulator of inflammatory cytokines, and it plays important roles in numerous conditions, including inflammatory and neuropathic pain, especially when discogenic pain is involved. Phosphorylation of IκB protein through IκB kinase (IKK) is the first step in the activation of NF-κB activation and the upregulation of NF-κB-responsive genes. PURPOSE: To investigate whether IKK inhibition alters the properties of pain-related neuropeptides in the rat lumbar degenerative intervertebral disc (IVD) model. STUDY DESIGN: Retrograde neurotracing and immunofluorescent investigation of pain-related neuropeptide (calcitonin gene-related peptide [CGRP]) in the sensory innervation of injured lumbar IVD in rat dorsal root ganglia (DRGs). METHODS: Forty female Sprague-Dawley rats were equally divided into four groups: naive, sham, and two agent-treated groups (vehicle [saline] group and anti-IKKβ [IMD-0560, IKKβ inhibitor] group). The L5-L6 IVDs of the agent-treated rats were exposed and injured by repeated punctures. The retrograde neurotracer Fluoro-Gold (FG) and corresponding treatment agents were intradiscally applied. In the sham group, FG alone was applied onto uninjured IVDs. One week later, L1-L3 DRGs were harvested and immunolabeled for CGRP as a pain marker. The proportions of FG-labeled CGRP-immunoreactive (-ir) DRG neurons were assessed. RESULTS: Fluoro-Gold-labeled DRG neurons were almost equally prevalent at each DRG level. The proportions of FG-labeled CGRP-ir DRG neurons in the two agent-treated groups were significantly increased in comparison with those in the naive and the sham groups (p<.05) and were significantly decreased in the anti-IKKβ group in comparison with that in the vehicle group (p<.05). CONCLUSIONS: The neuropeptide CGRP as a pain marker was upregulated in DRG neurons innervating the injured IVDs, and intradiscal inhibition of IKKβ significantly suppressed CGRP production in the DRG neurons innervating the rat IVD, suggesting the possible analgesic effect of IKKβ inhibition in discogenic pain.

Funding information:
  • Howard Hughes Medical Institute - MR/K001744/1(United States)
  • Wellcome Trust - 093855(United Kingdom)

Human mesenchymal precursor cells (Stro-1⁺) from spinal cord injury patients improve functional recovery and tissue sparing in an acute spinal cord injury rat model.

  • Hodgetts SI
  • Cell Transplant
  • 2013 Mar 14

Literature context:


Abstract:

This study aimed to determine the potential of purified (Stro-1(+)) human mesenchymal precursor cells (hMPCs) to repair the injured spinal cord (SC) after transplantation into T-cell-deficient athymic RNU nude rats following acute moderate contusive spinal cord injury (SCI). hMPCs were isolated from the bone marrow (BM) stroma of SCI patients and transplanted as a suspension graft in medium [with or without immunosuppression using cyclosporin A (CsA)]. Extensive anatomical analysis shows statistically significant improvement in functional recovery, tissue sparing, and cyst reduction. We provide quantitative assessment of supraspinal projections in combination with functional outcomes. hMPC-transplanted animals consistently achieved mean BBB scores of 15 at 8 weeks post injury. Quantitative histological staining revealed that graft-recipient animals possessed more intact spinal tissue and reduced cyst formation than controls. Fluorogold (FG) retrograde tracing revealed sparing/regeneration of supraspinal and local propriospinal axonal pathways, but no statistical differences were observed compared to controls. Immunohistochemical analysis revealed increased serotonergic (5-HT) and sensory (CGRP) axonal growth within and surrounding transplanted donor hMPCs 2 weeks posttransplantation, but no evidence of hMPC transdifferentiation was seen. Although hMPCs initially survive at 2 weeks posttransplantation, their numbers were dramatically reduced and no cells were detected at 8 weeks posttransplantation using retroviral/lentiviral GFP labeling and a human nuclear antigen (HNA) antibody. Additional immunosuppression with CsA did not improve hMPC survival or their ability to promote tissue sparing or functional recovery. We propose Stro-1(+)-selected hMPCs provide (i) a reproducible source for stem cell transplantation for SC therapy and (ii) a positive host microenvironment resulting in the promotion of tissue sparing/repair that subsequently improves behavioral outcomes after SCI. Our results provide a new candidate for consideration as a stem cell therapy for the repair of traumatic CNS injury.

Funding information:
  • NIAMS NIH HHS - R01AR053173(United States)

Treatment with basic fibroblast growth factor-incorporated gelatin hydrogel does not exacerbate mechanical allodynia after spinal cord contusion injury in rats.

  • Furuya T
  • J Spinal Cord Med
  • 2013 Mar 1

Literature context:


Abstract:

Besides stimulating angiogenesis or cell survival, basic fibroblast growth factor (bFGF) has the potential for protecting neurons in the injured spinal cord. OBJECTIVE: To investigate the effects of a sustained-release system of bFGF from gelatin hydrogel (GH) in a rat spinal cord contusion model. METHODS: Adult female Sprague-Dawley rats were subjected to a spinal cord contusion injury at the T10 vertebral level using an IH impactor (200 kdyn). One week after contusion, GH containing bFGF (20 µg) was injected into the lesion epicenter (bFGF - GH group). The GH-only group was designated as the control. Locomotor recovery was assessed over 9 weeks by Basso, Beattie, Bresnahan rating scale, along with inclined plane and Rota-rod testing. Sensory abnormalities in the hind paws of all the rats were evaluated at 5, 7, and 9 weeks. RESULTS: There were no significant differences in any of the motor assessments at any time point between the bFGF - GH group and the control GH group. The control GH group showed significantly more mechanical allodynia than did the group prior to injury. In contrast, the bFGF - GH group showed no statistically significant changes of mechanical withdrawal thresholds compared with pre-injury. CONCLUSION: Our findings suggest that bFGF-incorporated GH could have therapeutic potential for alleviating mechanical allodynia following spinal cord injury.

Funding information:
  • Medical Research Council - G0001354(United Kingdom)

Visualization of spinal afferent innervation in the mouse colon by AAV8-mediated GFP expression.

  • Schuster DJ
  • Neurogastroenterol. Motil.
  • 2013 Feb 22

Literature context:


Abstract:

BACKGROUND: Primary afferent neurons whose cell bodies reside in thoracolumbar and lumbosacral dorsal root ganglia (DRG) innervate colon and transmit sensory signals from colon to spinal cord under normal conditions and conditions of visceral hypersensitivity. Histologically, these extrinsic afferents cannot be differentiated from intrinsic fibers of enteric neurons because all known markers label neurons of both populations. Adeno-associated virus (AAV) vectors are capable of transducing DRG neurons after intrathecal administration. We hypothesized that AAV-driven overexpression of green fluorescent protein (GFP) in DRG would enable visualization of extrinsic spinal afferents in colon separately from enteric neurons. METHODS: Recombinant AAV serotype 8 (rAAV8) vector carrying the GFP gene was delivered via direct lumbar puncture. Green fluorescent protein labeling in DRG and colon was examined using immunohistochemistry. KEY RESULTS: Analysis of colon from rAAV8-GFP-treated mice demonstrated GFP-immunoreactivity (GFP-ir) within mesenteric nerves, smooth muscle layers, myenteric plexus, submucosa, and mucosa, but not in cell bodies of enteric neurons. Notably, GFP-ir colocalized with CGRP and TRPV1 in mucosa, myenteric plexus, and globular-like clusters surrounding nuclei within myenteric ganglia. In addition, GFP-positive fibers were observed in close association with blood vessels of mucosa and submucosa. Analysis of GFP-ir in thoracolumbar and lumbosacral DRG revealed that levels of expression in colon and L6 DRG appeared to be related. CONCLUSIONS & INFERENCES: These results demonstrate the feasibility of gene transfer to mouse colonic spinal sensory neurons using intrathecal delivery of AAV vectors and the utility of this approach for histological analysis of spinal afferent nerve fibers within colon.

Funding information:
  • NLM NIH HHS - R01 LM06845(United States)

Vesicular glutamate transporters in axons that innervate the human dental pulp.

  • Paik SK
  • J Endod
  • 2012 Apr 14

Literature context:


Abstract:

INTRODUCTION: Vesicular glutamate transporters (VGLUTs) are involved in the transport of transmitter glutamate into synaptic vesicles and are used as markers for glutamatergic neurons. METHODS: To assess which types of VGLUTs are involved in the glutamate signaling in pulpal axons and to investigate their distribution, we performed light microscopic immunohistochemistry by using antibodies against VGLUT1, VGLUT2, calcitonin gene-related peptide, and Western blot analysis in human dental pulp. RESULTS: VGLUT1 was expressed in a large number of pulpal axons, especially in the peripheral pulp where the axons branch extensively. The VGLUT1 immunopositive axons showed bead-like appearance, and the majority of these also expressed calcitonin gene-related peptide. VGLUT2 was expressed in few axons throughout the pulp. CONCLUSIONS: Our findings suggest that VGLUT1 is involved mainly in the glutamate-mediated signaling of pain, primarily at the level of the peripheral pulp.

Funding information:
  • NEI NIH HHS - EY026065(United States)

Peripheral calcium-permeable AMPA receptors regulate chronic inflammatory pain in mice.

  • Gangadharan V
  • J. Clin. Invest.
  • 2011 Jun 21

Literature context:


Abstract:

α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-type (AMPA-type) glutamate receptors (AMPARs) play an important role in plasticity at central synapses. Although there is anatomical evidence for AMPAR expression in the peripheral nervous system, the functional role of such receptors in vivo is not clear. To address this issue, we generated mice specifically lacking either of the key AMPAR subunits, GluA1 or GluA2, in peripheral, pain-sensing neurons (nociceptors), while preserving expression of these subunits in the central nervous system. Nociceptor-specific deletion of GluA1 led to disruption of calcium permeability and reduced capsaicin-evoked activation of nociceptors. Deletion of GluA1, but not GluA2, led to reduced mechanical hypersensitivity and sensitization in models of chronic inflammatory pain and arthritis. Further analysis revealed that GluA1-containing AMPARs regulated the responses of nociceptors to painful stimuli in inflamed tissues and controlled the excitatory drive from the periphery into the spinal cord. Consequently, peripherally applied AMPAR antagonists alleviated inflammatory pain by specifically blocking calcium-permeable AMPARs, without affecting physiological pain or eliciting central side effects. These findings indicate an important pathophysiological role for calcium-permeable AMPARs in nociceptors and may have therapeutic implications for the treatment chronic inflammatory pain states.

Funding information:
  • Biotechnology and Biological Sciences Research Council - BB/F005806/1(United Kingdom)

Sodium depletion increases sympathetic neurite outgrowth and expression of a novel TMEM35 gene-derived protein (TUF1) in the rat adrenal zona glomerulosa.

  • Tran PV
  • Endocrinology
  • 2010 Oct 22

Literature context:


Abstract:

The adrenal zona glomerulosa (ZG) secretes aldosterone to regulate sodium balance. Chronic sodium restriction increases aldosterone accompanied by ZG expansion. The ZG is innervated by sympathetic, vasoactive intestinal polypeptide (VIP) and neuropeptide tyrosine (NPY), and sensory, calcitonin gene-related peptide, nerves. It is unclear whether innervation is affected by ZG growth. Therefore, we measured neurite outgrowth in the ZG of adult male rats after dietary sodium manipulation. In response to 1 wk sodium restriction, VIP and NPY fibers elongated in parallel with expansion of the ZG, shown by aldosterone synthase (AS) expression, but calcitonin gene-related peptide fibers were not affected. Sodium repletion resulted in parallel regression in VIP and NPY fiber length and AS expression. These results show that sympathetic, but not sensory, innervation is coordinated with ZG growth. Mediators underlying changes in innervation are unknown; therefore, we characterized a novel gene TMEM35 [termed the unknown factor-1 (TUF1) due to its unknown function] that shows extensive overlap with AS in ZG. After sodium restriction, TUF1 expanded in parallel with the ZG. TUF1 bound the low-affinity neurotrophin receptor, p75NTR, which was expressed in NPY fibers and showed a response similar to TUF1 after sodium manipulation. TUF1- p75NTR binding was competitively displaced by nerve growth factor but not by TUF1 lacking the p75NTR binding motif. Moreover, TUF1 mRNA in rat ZG cells increased after angiotensin II exposure in vitro. Collectively, these findings suggest that TMEM35/TUF1 is a candidate for modulating neurite outgrowth in the ZG after sodium depletion.

Funding information:
  • NIGMS NIH HHS - RC2GM092519(United States)

Differential localization of vesicular glutamate transporters and peptides in corneal afferents to trigeminal nucleus caudalis.

  • Hegarty DM
  • J. Comp. Neurol.
  • 2010 Sep 1

Literature context:


Abstract:

Trigeminal afferents convey nociceptive information from the corneal surface of the eye to the trigeminal subnucleus caudalis (Vc). Trigeminal afferents, like other nociceptors, are thought to use glutamate and neuropeptides as neurotransmitters. The current studies examined whether corneal afferents contain both neuropeptides and vesicular glutamate transporters. Corneal afferents to the Vc were identified by using cholera toxin B (CTb). Corneal afferents project in two clusters to the rostral and caudal borders of the Vc, regions that contain functionally distinct nociceptive neurons. Thus, corneal afferents projecting to these two regions were examined separately. Dual immunocytochemical studies combined CTb with either calcitonin gene-related peptide (CGRP), substance P (SP), vesicular glutamate transporter 1 (VGluT1), or VGluT2. Corneal afferents were more likely to contain CGRP than SP, and corneal afferents projecting to the rostral region were more likely to contain CGRP than afferents projecting caudally. Overall, corneal afferents were equally likely to contain VGluT1 or VGluT2. Together, 61% of corneal afferents contained either VGluT1 or VGluT2, suggesting that some afferents lack a VGluT. Caudal corneal afferents were more likely to contain VGluT2 than VGluT1, whereas rostral corneal afferents were more likely to contain VGluT1 than VGluT2. Triple-labeling studies combining CTb, CGRP, and VGluT2 showed that very few corneal afferents contain both CGRP and VGluT2, caudally (1%) and rostrally (2%). These results suggest that most corneal afferents contain a peptide or a VGluT, but rarely both. Our results are consistent with a growing literature suggesting that glutamatergic and peptidergic sensory afferents may be distinct populations.

Funding information:
  • NIBIB NIH HHS - EB008400(United States)

Inhibition of inflammatory pain by activating B-type natriuretic peptide signal pathway in nociceptive sensory neurons.

  • Zhang FX
  • J. Neurosci.
  • 2010 Aug 11

Literature context:


Abstract:

B-type natriuretic peptide (BNP) has been known to be secreted from cardiac myocytes and activate its receptor, natriuretic peptide receptor-A (NPR-A), to reduce ventricular fibrosis. However, the function of BNP/NPR-A pathway in the somatic sensory system has been unknown. In the present study, we report a novel function of BNP in pain modulation. Using microarray and immunoblot analyses, we found that BNP and NPR-A were expressed in the dorsal root ganglion (DRG) of rats and upregulated after intraplantar injection of complete Freund's adjuvant (CFA). Immunohistochemistry showed that BNP was expressed in calcitonin gene-related peptide (CGRP)-containing small neurons and IB4 (isolectin B4)-positive neurons, whereas NPR-A was present in CGRP-containing neurons. Application of BNP reduced the firing frequency of small DRG neurons in the presence of glutamate through opening large-conductance Ca2+-activated K+ channels (BKCa channels). Furthermore, intrathecal injection of BNP yielded inhibitory effects on formalin-induced flinching behavior and CFA-induced thermal hyperalgesia in rats. Blockade of BNP signaling by BNP antibodies or cGMP-dependent protein kinase (PKG) inhibitor KT5823 [(9S,10R,12R)-2,3,9,10,11,12-hexahydro-10-methoxy-2,9-dimethyl-1-oxo-9,12-epoxy-1H-diindolo[1,2,3-fg:3',2',1'-kl]pyrrolo[3,4-i][1,6]benzodiazocine-10-carboxylic acid methyl ester] impaired the recovery from CFA-induced thermal hyperalgesia. Thus, BNP negatively regulates nociceptive transmission through presynaptic receptor NPR-A, and activation of the BNP/NPR-A/PKG/BKCa channel pathway in nociceptive afferent neurons could be a potential strategy for inflammatory pain therapy.

Funding information:
  • NCRR NIH HHS - RR-08605(United States)

Differential adeno-associated virus mediated gene transfer to sensory neurons following intrathecal delivery by direct lumbar puncture.

  • Vulchanova L
  • Mol Pain
  • 2010 May 28

Literature context:


Abstract:

BACKGROUND: Neuronal transduction by adeno-associated viral (AAV) vectors has been demonstrated in cortex, brainstem, cerebellum, and sensory ganglia. Intrathecal delivery of AAV serotypes that transduce neurons in dorsal root ganglia (DRG) and spinal cord offers substantial opportunities to 1) further study mechanisms underlying chronic pain, and 2) develop novel gene-based therapies for the treatment and management of chronic pain using a non-invasive delivery route with established safety margins. In this study we have compared expression patterns of AAV serotype 5 (AAV5)- and AAV serotype 8 (AAV8)-mediated gene transfer to sensory neurons following intrathecal delivery by direct lumbar puncture. RESULTS: Intravenous mannitol pre-treatment significantly enhanced transduction of primary sensory neurons after direct lumbar puncture injection of AAV5 (rAAV5-GFP) or AAV8 (rAAV8-GFP) carrying the green fluorescent protein (GFP) gene. The presence of GFP in DRG neurons was consistent with the following evidence for primary afferent origin of the majority of GFP-positive fibers in spinal cord: 1) GFP-positive axons were evident in both dorsal roots and dorsal columns; and 2) dorsal rhizotomy, which severs the primary afferent input to spinal cord, abolished the majority of GFP labeling in dorsal horn. We found that both rAAV5-GFP and rAAV8-GFP appear to preferentially target large-diameter DRG neurons, while excluding the isolectin-B4 (IB4) -binding population of small diameter neurons. In addition, a larger proportion of CGRP-positive cells was transduced by rAAV5-GFP, compared to rAAV8-GFP. CONCLUSIONS: The present study demonstrates the feasibility of minimally invasive gene transfer to sensory neurons using direct lumbar puncture and provides evidence for differential targeting of subtypes of DRG neurons by AAV vectors.

Funding information:
  • NHLBI NIH HHS - HL059836(United States)

A key role for gp130 expressed on peripheral sensory nerves in pathological pain.

  • Andratsch M
  • J. Neurosci.
  • 2009 Oct 28

Literature context:


Abstract:

Interleukin-6 (IL-6) is a key mediator of inflammation. Inhibitors of IL-6 or of its signal transducing receptor gp130 constitute a novel class of anti-inflammatory drugs, which raise great hopes for improved treatments of painful inflammatory diseases such as rheumatoid arthritis. IL-6 and gp130 may enhance pain not only indirectly through their proinflammatory actions but also through a direct action on nociceptors (i.e., on neurons activated by painful stimuli). We found indeed that the IL-6/gp130 ligand-receptor complex induced heat hypersensitivity both in vitro and in vivo. This process was mediated by activation of PKC-delta via Gab1/2/PI(3)K and subsequent regulation of TRPV1, a member of the transient receptor potential (TRP) family of ion channels. To assess the relevance of this direct pain promoting effect of IL-6, we generated conditional knock-out mice, which lack gp130 specifically in nociceptors, and tested them in models of inflammatory and tumor-induced pain. These mice showed significantly reduced levels of inflammatory and tumor-induced pain but no changes in immune reactions or tumor growth. Our results uncover the significance of gp130 expressed in peripheral pain sensing neurons in the pathophysiology of major clinical pain disorders and suggest their use as novel pain relieving agents in inflammatory and tumor pain.

Differential effects of anti-Nogo-A antibody treatment and treadmill training in rats with incomplete spinal cord injury.

  • Maier IC
  • Brain
  • 2009 Jun 26

Literature context:


Abstract:

Locomotor training on treadmills can improve recovery of stepping in spinal cord injured animals and patients. Likewise, lesioned rats treated with antibodies against the myelin associated neurite growth inhibitory protein, Nogo-A, showed increased regeneration, neuronal reorganization and behavioural improvements. A detailed kinematic analysis showed that the hindlimb kinematic patterns that developed in anti-Nogo-A antibody treated versus treadmill trained spinal cord injured rats were significantly different. The synchronous combined treatment group did not show synergistic effects. This lack of synergistic effects could not be explained by an increase in pain perception, sprouting of calcitonin gene-related peptide (CGRP) positive fibres or by interference of locomotor training with anti-Nogo-A antibody induced regeneration and sprouting of descending fibre tracts. The differential mechanisms leading to behavioural recovery during task-specific training and in regeneration or plasticity enhancing therapies have to be taken into account in designing combinatorial therapies so that their potential positive interactive effects can be fully expressed.

Endogenous tumor necrosis factor alpha (TNFalpha) requires TNF receptor type 2 to generate heat hyperalgesia in a mouse cancer model.

  • Constantin CE
  • J. Neurosci.
  • 2008 May 7

Literature context:


Abstract:

To provide a tool to investigate the mechanisms inducing and maintaining cancer-related pain and hyperalgesia, a soft tissue tumor/metastasis model was developed that is applicable in C57BL/6J wild-type and transgenic mice. We show that the experimental tumor-induced heat hyperalgesia and nociceptor sensitization were prevented by systemic treatment with the tumor necrosis factor alpha (TNFalpha) antagonist etanercept. In naive mice, exogenous TNFalpha evoked heat hyperalgesia in vivo and sensitized nociceptive nerve fibers to heat in vitro. TNFalpha enhanced the expression of the nociceptor-specific heat transducer ion channel transient receptor potential vanilloid 1 (TRPV1) and increased the amplitudes of capsaicin and heat-activated ionic currents via p38/MAP (mitogen-activated protein) kinase and PKC (protein kinase C). Deletion of the tumor necrosis factor receptor type 2 (TNFR2) gene attenuated heat hyperalgesia and prevented TRPV1 upregulation in tumor-bearing mice, whereas TNFR1 gene deletion played a minor role. We propose endogenous TNFalpha as a key player in cancer-related heat hyperalgesia and nociceptor sensitization that generates TRPV1 upregulation and sensitization via TNFR2.

Funding information:
  • Wellcome Trust - BB/C003926/1(United Kingdom)

Extramedullary chitosan channels promote survival of transplanted neural stem and progenitor cells and create a tissue bridge after complete spinal cord transection.

  • Nomura H
  • Tissue Eng Part A
  • 2008 May 4

Literature context:


Abstract:

Transplantation of neural stem and progenitor cells (NSPCs) is a promising strategy for repair after spinal cord injury. However, the epicenter of the severely damaged spinal cord is a hostile environment that results in poor survival of the transplanted NSPCs. We examined implantation of extramedullary chitosan channels seeded with NSPCs derived from transgenic green fluorescent protein (GFP) rats after spinal cord transection (SCT). At 14 weeks, we assessed the survival, maturation, and functional results using NSPCs harvested from the brain (brain group) or spinal cord (SC group) and seeded into chitosan channels implanted between the cord stumps after complete SCT. Control SCT animals had empty chitosan channels or no channels implanted. Channels seeded with brain or spinal cord-derived NSPCs showed a tissue bridge, although the bridges were thicker in the brain group. Both cell types showed long-term survival, but the number of surviving cells in the brain group was approximately five times as great as in the SC group. In both the brain and SC groups at 14 weeks after transplantation, many host axons were present in the center of the bridge in association with the transplanted cells. At 14 weeks astrocytic and oligodendrocytic differentiation in the channels was 24.8% and 17.3%, respectively, in the brain group, and 31.8% and 9.7%, respectively, in the SC group. The channels caused minimal tissue reaction in the adjacent spinal cord. There was no improvement in locomotor function. Thus, implantation of chitosan channels seeded with NSPCs after SCT created a tissue bridge containing many surviving transplanted cells and host axons, although there was no functional improvement.

Funding information:
  • NINDS NIH HHS - P30 NS045713(United States)

Expression of P2X3 receptor in the trigeminal sensory nuclei of the rat.

  • Kim YS
  • J. Comp. Neurol.
  • 2008 Feb 1

Literature context:


Abstract:

Trigeminal primary afferents expressing P2X(3) receptor are involved in the transmission of orofacial nociceptive information. However, little is known about their central projection pattern and ultrastructural features within the trigeminal brainstem sensory nuclei (TBSN). Here we use multiple immunofluorescence and electron microscopy to characterize the P2X(3)-immunopositive (+) neurons in the trigeminal ganglion and describe the distribution and synaptic organization of their central terminals within the rat TBSN, including nuclei principalis (Vp), oralis (Vo), interpolaris (Vi), and caudalis (Vc). In the trigeminal ganglion, P2X(3) immunoreactivity was mainly in small and medium-sized somata, but also frequently in large somata. Although most P2X(3) (+) somata costained for the nonpeptidergic marker IB4, few costained for the peptidergic marker substance P. Most P2X(3) (+) fibers in the sensory root of trigeminal ganglion (92.9%) were unmyelinated, whereas the rest were small myelinated. In the TBSN, P2X(3) immunoreactivity was dispersed in the rostral TBSN but was dense in the superficial laminae of Vc, especially in the inner lamina II. The P2X(3) (+) terminals contained numerous clear, round vesicles and sparse large, dense-core vesicles. Typically, they were presynaptic to one or two dendritic shafts and also frequently postsynaptic to axonal endings, containing pleomorphic vesicles. Such P2X(3) (+) terminals, showing glomerular shape and complex synaptic relationships, and those exhibiting axoaxonic contacts, were more frequently seen in Vp than in any other TBSN. These results suggest that orofacial nociceptive information may be transmitted via P2X(3) (+) afferents to all TBSN and that it may be processed differently in different TBSN.

Funding information:
  • NICHD NIH HHS - T32 HD055164(United States)

Evidence of altered epidermal nerve fiber morphology in adults with self-injurious behavior and neurodevelopmental disorders.

  • Symons FJ
  • Pain
  • 2008 Jan 18

Literature context:


Abstract:

The purpose of this preliminary study was to examine the morphology and neuropeptide density of epidermal nerve fibers quantified through skin biopsy samples from three adults with neurodevelopmental disorders and chronic self-injurious behavior (SIB) secondary to mental retardation compared with non-SIB normal IQ controls. A cross-sectional design was used with 3mm punch skin biopsies collected from each participant from non-self-injurious body sites and compared with site-matched existing normal control skin samples. The study was conducted at an outpatient clinic. The primary dependent measure for the morphology analyses was the coefficient of variation (CV) to quantify the mean gap length between epidermal nerve fibers for each subject. Visual microscopic examination and quantitative analysis of the microscopy images suggested there were morphological abnormalities (increased CV) in the epidermal nerve fibers among the chronic SIB cases. Substance P (SP) fiber density was increased with 2-3 times as many fibers in SIB subjects as control subjects. Additional empirical work is needed to clarify the relation between sensory innervation of the skin and self-injury to improve assessment and treatment outcomes.

Funding information:
  • NINDS NIH HHS - R01 NS031718(United States)

Anatomical evidence for enteric neuroimmune interactions in Peyer's patches.

  • Vulchanova L
  • J. Neuroimmunol.
  • 2007 Apr 2

Literature context:


Abstract:

Peyer's patches (PP), a key component of the gut-associated lymphoid tissue, serve as the primary inductive sites for intestinal immunity. In the present study, we addressed the hypothesis that the morphological features of PP innervation are consistent with an immunomodulatory role for the enteric nervous system. Laser scanning confocal microscopy was used to collect images through large tissue volumes, yielding a three-dimensional perspective of the neuronal network superimposed on PP follicles from porcine jejunum and human ileum. Peptidergic nerve fibers were found in close apposition to immunocytes within PP subepithelial domes and the adjacent villi. The results suggest that nerve fibers in PP may participate in neuroimmune cross-talk within individual antigen-sampling sites as well as integrate information across multiple antigen-sampling sites.

Funding information:
  • NIBIB NIH HHS - P41 EB015896(United States)

The majority of bladder sensory afferents to the rat lumbosacral spinal cord are both IB4- and CGRP-positive.

  • Hwang SJ
  • Brain Res.
  • 2005 Nov 16

Literature context:


Abstract:

The rat urinary bladder is innervated by neurons in dorsal root ganglia (DRG) that express the neuropeptides calcitonin gene-related peptide (CGRP) and substance P (SP), and a fraction of bladder afferents can bind the non-peptidergic marker isolectin B4 (IB4). We used histochemical binding and axonal tracing to identify the bladder afferents, and immunocytochemistry to determine the degree of colocalization of CGRP with IB4 in their cell bodies in DRG and in their central axons in the spinal cord. In the L6 DRG, about 60% of CGRP-positive neurons were also positive for IB4. In the spinal cord, IB4 and CGRP colocalized in fibers and terminals in the inner part of lamina II, the lateral collateral path, and the sacral parasympathetic nucleus (SPN). In SPN, the majority of IB4-positive fibers and terminals were also CGRP-positive. After injection of IB4 into the bladder wall, immunoreaction for IB4 was detected in SPN, but not in lamina II. These results suggest that most IB4-positive afferents from the bladder are also CGRP-positive, and that the distinction between peptidergic and non-peptidergic bladder afferents based on IB4 binding is of limited validity.

Funding information:
  • NIGMS NIH HHS - GM077678(United States)

Re-organization of P2X3 receptor localization on epidermal nerve fibers in a murine model of cancer pain.

  • Gilchrist LS
  • Brain Res.
  • 2005 May 24

Literature context:


Abstract:

To determine whether ATP and P2X3 receptors contribute to bone-cancer pain in a mouse model, immunohistochemical techniques were used to identify whether changes in the labeling of P2X3 receptors on epidermal nerve fibers (ENFs) occurred during tumor development. C3H mice were injected with osteolytic fibrosarcoma cells in and around the calcaneus bone. These mice exhibited mechanical hyperalgesia by day 10 post-implantation as assessed using von Frey monofilaments. Biopsies of the plantar skin overlying the tumor were obtained at days 10, 14, and 18 post-implantation. Confocal images were analyzed for the number of PGP 9.5, P2X3, and CGRP immunoreactive (ir) ENFs. The overall ENF population (PGP-ir) decreased progressively over time, whereas the subsets of P2X3-ir fibers demonstrated a modest increase and CGRP-ir nerve fibers remained fairly constant. Importantly, the proportion of CGRP-ir fibers that labeled for P2X3 increased from approximately 6% in control animals to nearly 30% at day 14 following tumor cell implantation. These studies demonstrate increased expression of P2X3 receptors on CGRP-ir ENFs during tumor growth and suggest a role for ATP in cancer-related pain.

Funding information:
  • NIGMS NIH HHS - RC2-GM92602(United States)

Changes of calcitonin gene-related peptide in primary sensory neurons and their central branch after nerve root compression of the dog.

  • Kobayashi S
  • Arch Phys Med Rehabil
  • 2005 Mar 10

Literature context:


Abstract:

OBJECTIVE: To investigate changes in axonal flow after nerve root compression by using immunohistochemical techniques to detect calcitonin gene-related peptide (CGRP), which is thought to be involved in pain sensation. DESIGN: Experimental, controlled study. SETTING: University medical school in Japan. ANIMALS: Forty adult mongrel dogs (weight, 7-15kg). INTERVENTIONS: In dogs, the lumbar nerve roots were compressed using 4 types of clips with different pressures. Changes of CGRP levels in the spinal dorsal horn, dorsal root, and dorsal root ganglia (DRG) were examined immunohistochemically after compression for 24 hours or for 1 week. MAIN OUTCOME MEASURES: CGRP-positive neurons and CGRP-positive fibers. RESULTS: After compression, axonal flow in the dorsal root was impaired, accumulation of CGRP was observed distal to the site of compression, and the number of DRG cells showing positively for CGRP decreased. Compression for 1 week resulted in a decrease in the number of CGRP-positive fibers in the spinal dorsal horn. CONCLUSIONS: These findings indicate that CGRP dynamics are modified by nerve compression.

Funding information:
  • NIMH NIH HHS - 5R01MH070370(United States)

Expression of vanilloid receptor TRPV1 in the rat trigeminal sensory nuclei.

  • Bae YC
  • J. Comp. Neurol.
  • 2004 Oct 4

Literature context:


Abstract:

Little is known about the central projection patterns of trigeminal afferent neurons expressing the vanilloid receptor TRPV1 and their coexpression of neuromodulatory peptides. To address these issues, we examined the distribution of TRPV1-positive neurons in the trigeminal ganglion (TG) and trigeminal sensory nuclei principalis (Vp), oralis (Vo), interpolaris (Vi), and caudalis (Vc) in the rat via light and electron microscopy. In addition, we studied the colocalization of TRPV1-positive neurons with substance P (SP) and calcitonin gene-related peptide (CGRP) via confocal microscopy. In TG, only small and medium-sized neurons were immunopositive for TRPV1. The staining for TRPV1 was found in axon collaterals in the dorsal parts of Vp, Vo, and Vi and in terminals and fibers throughout lamina I and the outer zone of lamina II (IIo) of Vc. With electron microscopy, TRPV1-positive fibers in the ascending and descending trigeminal tracts were found to be unmyelinated. Almost all TRPV1-positive terminals in Vc contained numerous large dense-core vesicles and formed synaptic contacts with single small dendrites. Multiple immunofluorescence revealed a high degree of colocalization of TRPV1 with SP and CGRP in TG neurons as well as in fibers and terminals confined to laminae I and IIo of Vc. These results suggest that the central projections of unmyelinated (C) afferents sensitive to noxious heat and capsaicin are organized differently between Vc and the rostral trigeminal nuclei and that Vc may play a role in the development of hyperalgesia.

Funding information:
  • Wellcome Trust - 089275(United Kingdom)

Wounds increase activin in skin and a vasoactive neuropeptide in sensory ganglia.

  • Cruise BA
  • Dev. Biol.
  • 2004 Jul 1

Literature context:


Abstract:

Successful healing of skin wounds requires sensory innervation and the release of vasoactive neuropeptides that dilate blood vessels and deliver serum proteins to the wound, and that cause pain that protects from further injury. Activin has been proposed as a target-derived regulator of sensory neuropeptides during development, but its role in the mature nervous system is unknown. While adult skin contains a low level of activin, protein levels in skin adjacent to a wound increase rapidly after an excision. Neurons containing the neuropeptide calcitonin gene-related peptide (CGRP) increased in sensory ganglia that projected to the wounded skin, but not in ganglia that projected to unwounded skin, suggesting that neurons respond to a local skin signal. Indeed, many adult sensory neurons respond with increased CGRP expression to the application of activin in vitro and utilize a smad-mediated signal transduction pathway in this response. A second skin-derived factor nerve growth factor (NGF) also increased in wounded skin and increased CGRP in cultured adult dorsal root ganglia (DRG) neurons but with lower efficacy. Together, these data support the hypothesis that activin made by skin cells regulates changes in sensory neuropeptides following skin injury, thereby promoting vasodilation and wound healing.

Funding information:
  • NIGMS NIH HHS - 1R15GM94732-1(United States)

The role of calcitonin gene-related peptide in cutaneous immunosuppression induced by repeated subinflammatory ultraviolet irradiation exposure.

  • Legat FJ
  • Exp. Dermatol.
  • 2004 Apr 16

Literature context:


Abstract:

Ultraviolet (UV) light is an effective treatment for skin disorders like psoriasis in which the cutaneous neurosensory system may have a pathogenic role. In this study, we examined the possibility that UV modulation of the cutaneous neurosensory system and calcitonin gene-related peptide (CGRP) may contribute to local immunosuppression mediated by repeated subinflammatory UV irradiation. Our results indicated that exposure of hairless mice to subinflammatory UV three times weekly for 4 weeks significantly increased the number of epidermal nerve fibers (ENFs) immunoreactive for CGRP without altering the total number of ENFs. The skin content of CGRP as measured by enzyme-linked immunosorbent assay was also significantly increased after exposure to this dose of UV. These effects were most apparent 1 day after the last UV exposure and declined 1 week after UV. The role of CGRP in UV-induced immunosuppression of contact hypersensitivity was then examined. Our results indicated that UV suppression of epicutaneous 2,4-dinitro-1-fluorobenzene (DNFB) sensitization could be significantly inhibited by a systemically administered CGRP receptor antagonist. A broad-spectrum sunscreen applied before UV exposure inhibited increased cutaneous CGRP and blocked immunosuppression. These findings support a role for CGRP in the local immunosuppression caused by chronic, repeated subinflammatory UV exposure.

Funding information:
  • NIDA NIH HHS - R01DA030304(United States)

Novel distribution of calcitonin gene-related peptide in rodent subcommissural organs.

  • Hung Tsai M
  • Neuroreport
  • 2003 Oct 6

Literature context:


Abstract:

For the first time we showed the presence of CGRP immunoreactivity in the SCO of golden hamsters, Wistar rats and Mongolian gerbils. In hamsters, the intense CGRP-like immunoreactivity was detected in the whole SCO, including Reissner's fiber- and granule-like structures at the ventricular surface of the SCO. The CGRP-positive hypendymal cells were frequently in contact with local blood vessels and some of them were situated intimately to the leptomeningeal space. In the SCOs of rats and gerbils, only the supranuclear area and apical cytoplasm of the ependymal cells were positive for CGRP, whereas the basal pole of the cells and the hypendyma were CGRP-negative. The existence of CGRP in rodents SCO was confirmed by the expression of CGRP mRNA in rat SCO by RT-PCR. The present results indicate that the SCOs of rodent species contain CGRP that may be in part synthesized by ependymocytes themselves. A species difference in the CGRP distributions of rodents SCOs may therefore imply its different synthesis rates or release pathways.

Funding information:
  • NIAID NIH HHS - K22 AI093595(United States)

Mite allergen induces allergic dermatitis with concomitant neurogenic inflammation in mouse.

  • Huang CH
  • J. Invest. Dermatol.
  • 2003 Aug 25

Literature context:


Abstract:

Pathogenesis of atopic dermatitis involved the interactions of immune and neuroendocrine systems. Here we describe a mouse model for atopic dermatitis with concomitant neurogenic inflammation, by epicutaneous sensitization with a dust mite allergen. Allergen patching resulted in localized dermatitis characterized by pronounced epidermal hyperplasia and spongiosis, which was associated with infiltration of eosinophils and neutrophils, degranulated mast cells, CD4+ and CD8+ T cells, and dendritic cells. There was increased innervation of calcium gene related peptides and substance P in inflamed skins, interactions between nerve fibers and mast cells were seen, indicating the coexistence of neurogenic inflammation. Splenic T cells produced T helper 2-polarized cytokines in response to allergen stimulation in vitro, indicating systemic allergen sensitization. This is the first report of a mouse model of eczema, accompanied by neurogenic inflammation, which shows close resemblance to human allergic diseases. This work supports the notion that the skin is an important site for the initiation of primary allergen sensitization. Besides, this model may also be useful for study of other stress-associated neuroinflammatory skin disorders such as neurogenic pruritus and psoriasis.

Funding information:
  • NINDS NIH HHS - R01NS073768(United States)

Ectopic sympathetic preganglionic neurons maintain proper connectivity in the reeler mutant mouse.

  • Yip YP
  • Neuroscience
  • 2003 Apr 17

Literature context:


Abstract:

The location of sympathetic preganglionic neurons (SPN) in the spinal cord of the reeler mouse mutant is abnormal. Instead of their normal location in the intermediolateral column, the majority of SPN in the reeler cluster around the central canal. To determine whether ectopically located SPN in the reeler form appropriate synaptic connections with their pre- and postsynaptic partners, we examined 1). whether the axons of descending neural pathways that normally terminate on SPN follow them to their ectopic location, and 2). whether the central autonomic neural circuit that controls sympathetic output to the kidney is organized normally in the reeler. Using antibodies against tyrosine hydroxylase, serotonin, neuropeptide Y, substance P and calcitonin gene-related peptide as markers for adrenergic, serotonergic and peptidergic terminals, we found that axons which normally innervate SPN follow these neurons to their ectopic spinal location in the reeler. Injection of pseudorabies virus into the kidney of wild type and reeler mutant mice revealed similar patterns of renal sympathetic and pre-sympathetic control circuits in the spinal cord, brainstem and forebrain. These results indicate that the presynaptic inputs and postsynaptic targets of SPN in the reeler are normal, despite the ectopic spinal location of their cell bodies.

Funding information:
  • Howard Hughes Medical Institute - R01NS036715(United States)

Capsaicin-sensitive extrinsic afferents are involved in acid-induced activation of distinct myenteric neurons in the rat stomach.

  • Schicho R
  • Neurogastroenterol. Motil.
  • 2003 Feb 17

Literature context:


Abstract:

Challenge of the rat gastric mucosa with 0.5 mol L(-1) HCl activates nitrergic neurons in the myenteric plexus as visualized by c-Fos immunohistochemistry. In the present study, we characterized the activated neurons more extensively by their chemical coding and investigated whether a neural pathway that involves capsaicin-sensitive extrinsic afferents and/or cholinergic neurons transmitting via nicotinic receptors contributes to the activation of myenteric neurons. In multiple labelling experiments, c-Fos was examined for co-localization with nitric oxide synthase (NOS), vasoactive intestinal peptide (VIP), neuropeptide Y (NPY), enkephalin (ENK), gastrin-releasing peptide (GRP), substance P (SP), calbindin D-28k (CALB) and neurofilament 145 (NF 145). All c-Fos-positive neurons were immunoreactive for NOS, VIP, NPY and NF 145, but not for SP, ENK, GRP and CALB. Nerve fibres co-expressing NOS, VIP and NPY were predominantly found in the external muscle layer and in the muscularis mucosae but rarely in the mucosa. Pre-treatment with capsaicin or hexamethonium or a combination of both pre-treatments reduced HCl-induced c-Fos expression by 54, 66 and 63%, respectively. Acid challenge of the stomach, therefore, leads to activation of presumably inhibitory motor neurons responsible for muscle relaxation. Activation of these neurons is partly mediated by capsaicin-sensitive afferents and involves ganglionic transmission via nicotinic receptors.

Funding information:
  • NCRR NIH HHS - P40 RR012546(United States)

Repeated subinflammatory ultraviolet B irradiation increases substance P and calcitonin gene-related peptide content and augments mustard oil-induced neurogenic inflammation in the skin of rats.

  • Legat FJ
  • Neurosci. Lett.
  • 2002 Sep 6

Literature context:


Abstract:

The cutaneous neurosensory system is suggested to be involved in the pathophysiology of pruritus and skin diseases such as psoriasis. We investigated if repeated subinflammatory doses of ultraviolet B (UVB) irradiation similar to those used to treat pruritus or psoriasis would affect the cutaneous neurosensory system. Sprague-Dawley rats were irradiated thrice weekly for 2-4 weeks with subinflammatory doses of UVB. Three days after the last UVB exposure: (i), the skin contents of substance P (SP), calcitonin gene-related peptide (CGRP), and nerve growth factor (NGF) were quantified; (ii), the skin nerve fiber density was observed; and (iii), the effect of UVB on mustard oil-induced neurogenic inflammation was determined. UV exposure significantly increased SP and CGRP content and mustard oil-induced neurogenic inflammation in UV-irradiated but not non-irradiated skin; however, it did not affect cutaneous NGF content or overall nerve fiber density. These data suggest that repeated subinflammatory UVB irradiation locally increases the content of cutaneous SP and CGRP by an increase of neuropeptide content of nerve fibers rather than by an increase of overall nerve fiber density.

Funding information:
  • NCI NIH HHS - P30 CA142543(United States)

Adrenal splanchnic innervation modulates adrenal cortical responses to dehydration stress in rats.

  • Ulrich-Lai YM
  • Neuroendocrinology
  • 2002 Aug 9

Literature context:


Abstract:

Classically, the production of glucocorticoids by the adrenal gland is thought to be controlled exclusively by adrenocorticotropic hormone (ACTH). However, there are several examples in stressed humans and animals of increased plasma glucocorticoids in the absence of increased plasma ACTH, suggesting that an additional, non-ACTH mechanism(s) may contribute to the control of glucocorticoid production. The present studies were designed to determine the role of the thoracic splanchnic nerve in controlling plasma corticosterone levels in response to chronic water deprivation in rats, a model previously reported to demonstrate dissociations between plasma corticosterone and ACTH. Briefly, rats underwent right unilateral adrenalectomy and left thoracic splanchnic nerve transection or sham transection. After recovery, rats were water deprived for 48 h or given free access to water, and then sacrificed for collection of plasma and adrenal glands. Water deprivation resulted in consistent, robust increases in plasma corticosterone that were attenuated by splanchnic nerve transection, in the absence of changes in post-dehydration plasma ACTH. Adrenal content of steroidogenic acute regulatory factor (StAR) and cyclic AMP (cAMP) were increased after dehydration; splanchnic nerve transection decreased post-dehydration adrenal cAMP, but not StAR. Splanchnic nerve transection also attenuated plasma corticosterone responses to submaximal doses of ACTH in dexamethasone-blocked, dehydrated rats, suggesting a decreased adrenal sensitivity to ACTH. Collectively, the present results demonstrate that the thoracic splanchnic nerve normally augments the adrenal corticosterone response to dehydration stress by increasing adrenal sensitivity to ACTH, and this augmentation is associated with elevations in adrenal cAMP content. These data support the hypothesis that the splanchnic innervation of the adrenal gland represents an additional physiological mechanism to control stress-induced adrenal cortical responses in vivo.

Funding information:
  • NIDDK NIH HHS - U24 DK059637(United States)

Cell relationship in a Wistar rat model of spontaneous prostatitis.

  • Keith IM
  • J. Urol.
  • 2001 Jul 3

Literature context:


Abstract:

PURPOSE: Prostatitis in men is a painful, noninfectious inflammatory condition. It is similar to interstitial cystitis which is associated with increased bladder mast cell and sensory nerve fiber density as well as suprapubic pain. Certain strains of rats may provide a useful model for studies of the development of spontaneous prostatitis. We evaluated the time course, and involvement of mast cells and sensory nerve fibers in this process using Wistar rats. MATERIALS AND METHODS: The prostates of 4, 6, 8, 10 and 13-week-old male Wistar rats were examined for the degree of inflammation, innervation, mast cell density and nerve mast cell relationship using histochemical and immunocytochemical studies. Bacterial cultures of tissue were performed at 13 weeks. RESULTS: The inflammatory cell index increased progressively with age. Inflammation was moderate and consisted mostly of lymphocytes and macrophages associated with occasional glandular epithelial necrosis and edema. The density of nerve fibers immunoreacting with the neuronal marker protein gene produce 9.5 increased gradually with age and fibers immuno-positive for the sensory neuropeptide calcitonin gene-related peptide more than doubled by 13 weeks compared with by 4 weeks. The density of visible mast cells declined after 4 weeks in a pattern that corresponded with the increased percent of mast cells undergoing degranulation. For the mast cells with calcitonin gene-related peptide immuno-positive nerve fibers within a distance of 40 microm. distance correlated significantly with the degree of degranulation. Bacterial cultures were negative at 13 weeks. CONCLUSIONS: Our results confirm previous reports of spontaneous prostatitis in Wistar rats and indicate that moderate inflammation may occur in 80% of rats at as early as age 13 weeks. While the correlation of the nerve mast cell axis with mast cell degranulation does not prove our hypothesis of mast cell mediated inflammatory mediator release in the development of nonbacterial prostatitis, it suggests that such a relationship is possible.

Funding information:
  • NINDS NIH HHS - NS19904(United States)

Axon terminals containing CGRP-immunoreactivity form synapses with CRF- and Met-enkephalin-immunopositive neurons in the laterodorsal division of the bed nucleus of the stria terminalis in the rat.

  • Kozicz T
  • Brain Res.
  • 2001 Mar 2

Literature context:


Abstract:

The lateral division of the bed nucleus of the stria terminalis (BSTL) is an important forebrain structure that relays information between limbic structures and the hypothalamus. The BSTL displays a very dense calcitonin gene-related peptide-immunoreactive (-ir) fiber terminal network, and contains a substantial number of the corticotropin releasing factor (CRF)-ir neurons. Several Met-enkephalin-ir perikarya have also been observed in the BSTL. The distributions of CRF- and Met-enkephalin-ir neurons and that of the calcitonin gene-related peptide (CGRP)-ir axon terminals overlap within the BSTL, suggesting synaptic connections between CRF- and Met-enkephalin-ir neurons and axon terminals immunoreactive for CGRP. Double staining immunohistochemistry revealed that CGRP-ir axon terminals were within close proximity to dendrites or perikarya of corticotropin releasing factor and Met-enkephalin-ir neurons. When viewed at the electron microscopic level, axodendritic or axosomatic synapses between CGRP-ir fiber terminals and neurons immunoreactive for CRF and Met-enkephalin were detected. Most of the CRF-ir neurons project to brainstem centers, which modulate the physiological changes accompanying stress, whereas the Met-enkephalin-ir perikarya are most likely interneurons that often colocalize with GABA. The parabrachial nucleus, a vital autonomic center, is the primary source of CGRP-ir fiber terminals to the BSTL. The synaptic contacts between the CGRP axon terminals and CRF- and Met-enkephalin-ir neurons underlie the importance of connections between autonomic brainstem centers and BSTL, which can be fundamental in the modulatory control of endocrine, physiological and behavioral responses during stress.

Immunocytochemical study on the liver innervation in patients with cirrhosis.

  • Stoyanova II
  • Acta Histochem.
  • 2000 Nov 28

Literature context:


Abstract:

In the liver, the autonomic nervous system plays an important role in degenerative and inflammatory changes. The aim of the present study was to investigate the distribution of neuronal fibres containing neuropeptides in livers of 5 patients with cirrhosis by immunocytochemical localization at the light and electron microscopical level of substance P (SP), neuropeptide Y (NPY), somatostatin (SOM), and calcitonin gene-related peptide (CGRP). In patients with alcoholic cirrhosis, a decreased number of neuronal fibres was found in the portal tract and fibrous septa as well as in the sinusoids of regenerative nodules. NPY- and SP-immunoreactive neuronal fibres were more numerous than CGRP-containing fibres. They were located mainly in portal tracts. These findings led to the conclusion that peptidergic innervation plays a role in inflammatory and fibrotic changes in cirrhotic liver.

Funding information:
  • NIGMS NIH HHS - GM55507(United States)

Rat adrenal transplants are reinnervated: an invalid model of denervated adrenal cortical tissue.

  • Ulrich-Lai YM
  • J. Neuroendocrinol.
  • 2000 Sep 2

Literature context:


Abstract:

Adrenal autotransplantation is a widely used approach to investigate the potential for neural modulation of adrenal cortical function. It is believed that regenerating adrenal transplants are not reinnervated, thereby providing a model to investigate adrenal function in the absence of neural modulation. However, the hypothesis that adrenal transplants become reinnervated has not been directly tested. The purpose of the present study was to characterize the time course, extent, and nature of the reinnervation of the regenerating adrenal transplant and to assess whether the recovery of steroidogenic function and enzyme expression correlates temporally with the presence of innervation. Using immunohistofluorescent detection of tyrosine hydroxylase (TH), neuropeptide Y (NPY), calcitonin gene-related peptide (CGRP), and vasoactive intestinal peptide (VIP), the innervation of regenerating adrenals was assessed 14-30 days after transplantation of adrenal capsules beneath the kidney capsule in rats. Extensive reinnervation by TH-, NPY-, and VIP-positive fibres was present by 14 days after transplantation including regions of the adrenal capsule and cortex, with only minimal reinnervation by CGRP-positive fibres up to 30 days. TH- and NPY-positive chromaffin cells were also observed in the regenerating transplants. In addition, there was marked recovery of steroidogenic function and steroidogenic enzyme expression up to 30 days. The finding that nerve fibres are present in the transplants during the re-establishment of steroidogenic function and enzyme expression suggests that innervation may modulate the regeneration and functional recovery of adrenal transplants. In an attempt to prevent reinnervation of transplants, adrenal capsules were autotransplanted to denervated kidneys. Immunohistochemical analysis showed that, despite extensive denervation of the kidney tissue, the reinnervation and regeneration of the adrenal transplants still occurred. These data demonstrate the marked capacity of the regenerating adrenal to become reinnervated and reinforces the conclusion that adrenal transplants are an invalid model of denervated adrenal cortical tissue.

Increase in bombesin-like peptides in the spinal cord after dexamethasone treatment of adrenalectomized rats.

  • Westermark T
  • Neurosci. Lett.
  • 1999 Nov 19

Literature context:


Abstract:

The potential influence of corticosteroids on the bombesin (BN)-like peptide family is unknown. Therefore, the effects of adrenalectomy (ADX) on the nervous system of Sprague-Dawley rats, some of them being treated with high doses of the synthetic glucocorticoid dexamethasone (DEX), were investigated. After 8-10 days of treatment, the rats were sacrificed and tissues were prepared for radioimmunoassay (RIA) and immunohistochemical examination. We found an increase in BN-like immunoreactivity in the superficial layers of the dorsal horn of the lumbar spinal cord in the ADX + DEX animals. This increase was confirmed by RIA (P < 0.05). The observations show that the expression of BN-like peptides is influenced by glucocorticoids. The altered levels of BN-like peptides may be related to the trophic and antinociceptive effects previously reported for these peptides.

The significance of frequent and independent p53 and bcl-2 expression in large-cell neuroendocrine carcinomas of the lung.

  • Jiang SX
  • Mod. Pathol.
  • 1999 Apr 11

Literature context:


Abstract:

Both p53 and bcl-2 genes are involved in regulating cell death. Reports, however, concerning the relationship between p53 and bcl-2 expression are contradictory. Large-cell neuroendocrine carcinoma (LCNEC) of the lung is a newly recognized clinicopathologic entity. p53 mutation and bcl-2 overexpression are frequent in small-cell lung carcinoma (SCLC), and we observed a close correlation between bcl-2 expression and cellular neuroendocrine (NE) differentiation in non-SCLC, so we speculated that LCNEC, an NE tumor closely related to SCLC, would exhibit high incidence of both p53 alteration and bcl-2 expression. Immunohistochemical expression of p53 and bcl-2 was evaluated on consecutive sections of 26 LCNECs, including 4 combined LCNECs. p53 accumulation and diffuse bcl-2 staining were observed in 18 (69.2%) of 26 and 24 (92.3%) of 26 LCNECs, respectively, but their immunoreactivities showed no fixed distribution relevance on consecutive sections in individual tumors. Statistical analyses yielded no relationship between p53 and bcl-2 expression (P = .47). In all of the four combined LCNECs, p53 was identically either positive or negative in both tumor cell populations with and without NE differentiation. bcl-2 immunoreactivity was observed only for the tumor cells with NE phenotype in three of the four combined LCNECs and was diffuse among the NE tumor cells but geographic in distribution among the non-NE tumor cells of the remaining one combined LCNEC. Thus, our present findings suggest that p53 and bcl-2 are expressed independently and might have distinct expression significance in LCNECs. A high incidence of p53 expression in LCNECs and equal p53 expression profiles in NE and non-NE tumor cell populations of combined LCNECs suggest that p53 alteration is primarily involved in the tumorigenesis of LCNEC. On the other hand, frequent bcl-2 expression in pure LCNECs and selective bcl-2 expression in tumor cells with NE phenotype in combined LCNECs are suggestive of a role for bcl-2 in regulating cellular NE differentiation.

Ontogeny of innervation of rat and ovine fetal adrenals.

  • Engeland WC
  • Endocr. Res.
  • 1999 Apr 13

Literature context:


Abstract:

The formation of adrenocortical zonation occurs in rats during late gestation. Since adult cortical function is modulated by neural mediators, it is possible that the development of differentiated function is dependent on cortical innervation. The goal of this study was to compare the pattern and timing of rodent and ovine adrenal innervation during late organogenesis by staining with antibodies directed against the neuropeptides vasoactive intestinal peptide (VIP), calcitonin gene-related peptide (CGRP) and neuropeptide tyrosine (NPY) and the catecholamine biosynthetic enzyme, tyrosine hydroxylase (TOH). Rat adrenals were collected from fetal days 17-21 (term=21 days) and ovine adrenals from fetal days 101-136 (term=145 days). Adrenals were fixed, cryosectioned at 100 microns and immunostained using Cy3-conjugated secondary antibodies. In both species, staining of VIP, CGRP, NPY and TOH fibers was observed in the capsule and subcapsular layers of the cortex during gestation. In late gestation, VIP- and NPY-positive ganglions cells were observed near the medulla extending processes toward the outer cortex; in ovine adrenals, fibers from ganglion cells appeared to surround nests of outer cortical (presumably, zona glomerulosa) cells. These data show that phenotypically distinct neural elements appear at different stages of adrenocortical development. The presence of neural elements in contact with adrenal cortical cells supports the possibility for neural control of adrenocortical development.

Funding information:
  • NIGMS NIH HHS - DP2 GM119139(United States)

Regenerative effect of human recombinant NGF on capsaicin-lesioned sensory neurons in the adult rat.

  • Schicho R
  • Brain Res.
  • 1999 Jan 2

Literature context:


Abstract:

Nerve growth factor (NGF) has the ability to increase the content of peptide transmitter in intact primary sensory afferents of the adult rat. We have previously shown that NGF can also induce a refill of peptide transmitters in capsaicin-depleted peptidergic nerve terminals of the rat paw skin upon intraplantar injection. The present study was aimed at investigating the neurochemical, immunohistochemical and functional recovery of peripheral and central terminals of capsaicin-lesioned afferents following administration of recombinant human NGF-beta (rhNGF-beta). The systemic capsaicin treatment in adult rats by 50 mg/kg s.c. (day 0) was followed by intraplantar rhNGF-beta injections (4 micrograms each) into one hind paw on days 1, 2, 3, 5, 6 and by the analysis on day 8. The content of the marker peptide calcitonin gene-related peptide (CGRP) showed a 100% NGF-induced recovery in the peripheral (sciatic nerve) and central axons (lumbar dorsal roots) on the side of the NGF treatment and also in the contralateral sciatic nerve and lumbar dorsal roots. In the terminals of the hind paw skin, the recovery of the CGRP content, as measured by radioimmunoassay, was 100% in the plantar and 80% in the dorsal skin ipsilaterally, and 55% in the dorsal and plantar hind paw skin contralaterally. In the lumbar dorsal spinal cord, CGRP content recovered by 85% bilaterally. The morphological appearance of the sensory nerve terminals was visualized by CGRP-immunohistochemistry. In the paw skin, the CGRP-immunoreactive (CGRP-IR) nerve endings were restricted to a fragmentary subepidermal plexus after the capsaicin treatment, whereas the subsequent NGF treatment caused a bilateral recovery of the subepidermal plexus and an intact reinnervation of the epidermis and blood vessels with free nerve terminals. The capsaicin-induced fragmentation of the CGRP terminal plexus in laminae I and II of the lumbar spinal dorsal horn was also markedly repaired on both sides by the intraplantar NGF injections. The NGF treatment caused the CGRP nerve terminals in the spinal cord to regain their ability of releasing transmitter upon capsaicin stimulation as shown in tissue slice superfusion experiments. These results show that within one week, rhNGF-beta can induce a complete reinnervation of skin and spinal cord with intact CGRP-IR nerve terminals after an acute capsaicin lesion.

Funding information:
  • PHS HHS - HHSN271200723701C(United States)
  • Wellcome Trust - (United Kingdom)

Contribution of opioid receptors on primary afferent versus sympathetic neurons to peripheral opioid analgesia.

  • Zhou L
  • J. Pharmacol. Exp. Ther.
  • 1998 Aug 2

Literature context:


Abstract:

Opioid receptors are synthesized in dorsal root ganglia and transported into peripheral terminals of primary afferent neurons. Activation of such receptors results in antinociceptive effects that are most prominent in inflammation. In addition, opioid receptors located on sympathetic postganglionic neuron terminals may be involved in these effects. This study investigates the peripheral analgesic efficacy of the mu, delta and kappa receptor agonists [D-Ala2,N-Me-Phe4,Gly-ol5]-enkephalin, [D-Pen2,5]-enkephalin and trans-(+/-)3, 4-Dichloro-N-methyl-N-[2-(1-pyrrolidinyl)-cyclohexyl]-benzeneacetamid e, the effective number of peripheral mu, delta and kappa receptors in relation to the development of inflammation and the contribution of sympathetic vs. sensory neurons by use of capsaicin and 6-hydroxydopamine, respectively. In Wistar rats with Freund's adjuvant-induced hindpaw inflammation, antinociceptive effects of intraplantar [D-Ala2,N-Me-Phe4,Gly-ol5]-enkephalin (1.0-32 microg), [D-Pen2,5]-enkephalin (10-100 microg) and trans-(+/-)3, 4-Dichloro-N-methyl-N-[2-(l-pyrrolidiny)-cyclohexyl]-benzeneace tam ide (10-100 microg) were evaluated by paw pressure test. These effects increased linearly between 6 and 24 hr, but did not change between 24 and 96 hr of inflammation, whereas the doses of the irreversible antagonists beta-funaltrexamine, [D-Ala2,Leu5,Cys6]enkephalin or (+/-)-(5beta,7a,8beta)-3, 4-dichloro-N-[3-methylene-2-oxo-8-(1-pyrrolidinyl)-1-oxaspir[4, 5]dec-7-yl]benzeneacetamide required to abolish the respective agonist effects increased between 12 and 96 hr. Pretreatment with capsaicin (30, 50, 70 mg/kg s.c. over 3 days) but not with 6-hydroxydopamine (75 mg/kg i.p. over 3 days) reversed the hyperalgesia in inflamed paws and almost abolished antinociceptive effects of all three agonists. These results suggest that the increased opioid agonist efficacy is due to an increased number of peripheral opioid receptors at later stages of inflammation and that peripheral opioid antinociceptive effects are primarily mediated by mu, delta and kappa opioid receptors on primary afferent neurons.

Funding information:
  • NIGMS NIH HHS - R01 GM068851(United States)

Distribution and putative function of autonomic nerve fibres in the bill skin of the platypus (Ornithorhynchus anatinus).

  • Manger PR
  • Philos. Trans. R. Soc. Lond., B, Biol. Sci.
  • 1998 Jul 29

Literature context:


Abstract:

The electroreceptors located in the bill skin of the platypus are modified secretory glands. The electroreceptive nerve terminals form bare endings in close proximity to the duct of these glands. In this study, we describe the autonomic innervation of the glands and a separate specialized autonomic innervation of the epidermal portion of the glandular duct. A range of immunohistochemical labels showed that the gland cells of the electroreceptors have a non-noradrenergic (putative parasympathetic) innervation. Phalloidin labelling revealed a 'sphincter' of epidermal luminal cells that labelled strongly for actin. These actin-dense keratinocytes were seen to have a noradrenergic (putative sympathetic) innervation. Fine-diameter sensory fibres containing substance P (presumably C-fibre thermoreceptors or polymodal nociceptors) were observed to terminate in the superficial epidermis surrounding the pore of the gland. When the bill of the platypus is dry these pores were closed. However, when room temperature water was washed over the bill, the pores opened. It is proposed that this autonomic and sensory innervation, along with the actin sphincter, mediates the opening and closing of the pores. By doing this, the platypus prevents the desiccation of the bare electrosensory nerve terminals when it is out of the water, and it may also be a way to regulate the impedance of the internal electrical circuit presented to the water at the pores.

Funding information:
  • Biotechnology and Biological Sciences Research Council - BBF0083091(United Kingdom)

Corticotropin releasing factor-like immunoreactivity in afferent projections to the sacral spinal cord of the cat.

  • Kawatani M
  • J. Auton. Nerv. Syst.
  • 1996 Dec 14

Literature context:


Abstract:

Distribution and origin of corticotropin releasing factor (CRF) in the thoraco-lumbar and sacral spinal cord of the cat has been studied using immunohistochemical method. CRF immunoreactive (CRF-IR) nerve fibers and terminals were most prominent in dorsal part of sacral spinal cord. In the sacral segments of the spinal cord, immunoreactivity for CRF was detected in a prominent bundle of axons and varicosities extending from Lissauer's tract (LT) along the lateral edge of the superficial dorsal horn (laminae I and II) to laminae V at the base of the dorsal horn. Individual CRF-IR fibers passed from the bundle in ventral medial and ventrolateral directions to the dorsal commissure and the sacral preganglionic nucleus (SPN), respectively. The bundle of CRF-IR axons closely resembled vasoactive intestinal polypeptide (VIP) containing fibers in LT and on the lateral edge of the dorsal horn. Sacral dorsal root transection eliminated both the CRF and VIP fiber staining in the dorsal horn. Spinal transection at the T12-T13 segmental level did not influence the CRF- or VIP-IR. Less intense CRF-IR was also present in fibers in: (1) the dorsal lateral funiculus adjacent to LT, (2) the superficial layers of the dorsal horn and intermediolateral nucleus at thoracolumbar spinal levels, (3) the ventral horn, including Onuf's nucleus, (4) the intermediate gray matter including the dorsal gray commissure, and (5) the SPN. The similarity in the distribution of CRF-IR and pelvic nerve afferent projections in the sacral spinal cord raises the possibility that CRF may be a transmitter in afferent neurons innervating the pelvic viscera.

Funding information:
  • Biotechnology and Biological Sciences Research Council - JPA 1729(United Kingdom)

Intramyocardial arterial cushions of coronary vessels in animals and humans: morphology, occurrence and relation to heart disease.

  • Whelan NL
  • J. Vasc. Res.
  • 1996 Nov 12

Literature context:


Abstract:

The existence of coronary endoarterial cushions (CEC) in the human heart as nonpathological, functional entities has been debated, and CEC have been sparsely reported in animals. Arterial cushions are localized thickenings that protrude into the lumen of specific arteries. We have identified CEC in the rhesus monkey, dog, sheep, goat, pig, rabbit and rat, and in the human heart. Two distinct types are described: the ovoid CEC arranged singly, in pairs, or in groups of three to four, and the less common polypoid CEC seen primarily in humans. The highest incidence of CEC in rabbits and humans was in the left ventricle in arteries 150-488 microns in diameter. Light and electron microscopy demonstrated intimal location with smooth muscle cells surrounded by ground substance, collagen and elastin fibers in a highly organized pattern. Nerve fibers identified by their immunoreactivity with antiserum to the vasodilatory calcitonin-gene-related peptide contacted the CEC along the tunica media and were occasionally seen within CEC. Arrangement and histological composition of CEC suggest a role in the regulation of local blood flow and myocardial perfusion. In human hearts, the CEC density index correlated highly with the degree of heart disease. In subjects with high heart disease rating, increased connective tissue, lipid-like infiltration and calcification was seen within CEC, and foam cells were present in CEC of obese rabbits. This suggests that CEC in coronary arteries could be predisposed sites of atherosclerosis, and that injured CEC can cause coronary artery spasm and ischemia. We conclude that CEC occur in animals and humans as innervated intimal smooth muscle cushions that might have a role in myocardial perfusion and heart disease.

Funding information:
  • NHGRI NIH HHS - P41 HG00739(United States)

Nitric oxide nerves in the uterus are parasympathetic, sensory, and contain neuropeptides.

  • Papka RE
  • Cell Tissue Res.
  • 1995 Feb 26

Literature context:


Abstract:

Nitric oxide (NO) is synthesized in neurons and is a potent relaxor of vascular and nonvascular smooth muscle. The uterus contains abundant NO-synthesizing nerves which could be autonomic and/or sensory. This study was undertaken to determine: 1) the source(s) of NO-synthesizing nerves in the rat uterus and 2) what other neuropeptides or transmitter markers might coexist with NO in these nerves. Retrograde axonal tracing, utilizing Fluorogold injected into the uterine cervix, was employed for identifying sources of uterine-projecting neurons. NO-synthesizing nerves were visualized by staining for nicotinamide adenine dinucleotide phosphate (reduced)-diaphorase (NADPH-d) and immunostaining with an antibody against neuronal/type I NO synthase (NOS). NADPH-d-positive perikarya and terminal fibers were NOS-immunoreactive (-I). Some NOS-I/NADPH-d-positive nerves in the uterus are parasympathetic and originate from neurons in the pelvic paracervical ganglia (PG) and some are sensory and originate from neurons in thoracic, lumbar, and sacral dorsal root ganglia. No evidence for NOS-I/NADPH-d-positive sympathetic nerves in the uterus was obtained. Furthermore, double immunostaining revealed that in parasympathetic neurons, NOS-I/NADPH-d-reactivity coexists with vasoactive intestinal polypeptide, neuropeptide Y, and acetylcholinesterase and in sensory nerves, NOS-I/NADPH-d-reactivity coexists with calcitonin gene-related peptide and substance P. In addition, tyrosine hydroxylase(TH)-I neurons of the PG do not contain NOS-I/NADPH-d-reactivity, but some TH-I neurons are apposed by NOS-I varicosities. These results suggest NO-synthesizing nerves in the uterus are autonomic and sensory, and could play significant roles, possibly in conjunction with other putative transmitter agents, in the control of uterine myometrium and vasculature.

Funding information:
  • NIMH NIH HHS - R01 MH094639(United States)

Deafferentation-induced changes in neuropeptides of the adult rat dorsal horn following pronase injection of the sciatic nerve.

  • el-Bohy A
  • J. Comp. Neurol.
  • 1993 Oct 22

Literature context:


Abstract:

The effect of deafferentation on the neuropeptides substance P (SP), calcitonin gene-related peptide (CGRP), somatostatin (SS), and cholecystokinin (CCK) in the lumbar dorsal horn of the adult rat was examined by the indirect immunohistochemical method. Deafferentation was induced by injecting the sciatic nerve of anesthetized rats with proteolytic enzymes (20 mg pronase), which cause selective death of the nerve's ganglion cells and degeneration of their terminal arborization in the spinal cord. The density of immunolabel of each peptide was determined by using a computerized densitometry analysis system in two animal groups, i.e., short-term (10-13 days after injection) and long-term (4-9 months). In both groups, the deafferentation produced a significant ipsilateral depletion of CGRP, SP, CCK, and SS immunoreactivity. This depletion was limited to the area occupied by the sciatic terminals in the dorsal horn. In the long-term group, the loss of CGRP and SP staining was significantly less than that in the short-term animals, thus indicating partial recovery. A similar, but not statistically significant, trend was observed for CCK and SS. The large decrease in CGRP and SP seen in short-term animals reflects the large contribution of the sciatic nerve to the lumbar dorsal horn. The partial recovery of peptides demonstrates the plasticity of the nervous system and may parallel sprouting of primary afferents from other nerves, such as the saphenous nerve, as we have demonstrated in previous studies.

Funding information:
  • NIAID NIH HHS - 1R01AI066116-01(United States)

Peripheral peptidergic fibers of the trigeminal nerve in the olfactory bulb of the rat.

  • Finger TE
  • J. Comp. Neurol.
  • 1993 Aug 1

Literature context:


Abstract:

Axons immunoreactive for calcitonin gene-related peptide (CGRP) and substance P are present in the olfactory nerve, although few, if any, olfactory receptor cells contain immunocytochemically detectable levels of these peptides. The possible trigeminal origin of these fibers was tested by performing unilateral stereotaxic lesions of the ophthalmic division of the trigeminal nerve, followed 2-25 days later by immunocytochemistry for CGRP and substance P. As reported previously, free nerve endings immunoreactive for both peptides were found transversing the nasal epithelium on the unlesioned side. Also on the unlesioned side, peptidergic axons, immunoreactive for both CGRP and substance P, could be traced from the olfactory nerve into the glomerular layer throughout the olfactory bulb, but especially into its rostral third. Ipsilateral to the trigeminal ganglion lesion, such peptide-immunoreactive fibers were absent or markedly reduced in the bulb, nerve, and epithelium. These results indicate that the peripheral branches of the ophthalmic branch of the trigeminal nerve enter the olfactory bulb along with the olfactory nerve and terminate in the glomerular layer along with the olfactory axons. Ultrastructural analysis of the CGRP-immunoreactive terminals in the glomeruli reveal vesicle-filled axonal processes terminating in the absence of obvious pre- or postsynaptic specializations. Whether the trigeminal fibers in the bulb are functional, e.g., convey information to the olfactory bulb via an axon reflex, or relay information from the olfactory bulb to the brainstem trigeminal nuclei is unclear.

Funding information:
  • NHGRI NIH HHS - U54-HG004028(United States)

Medullary carcinoma of the thyroid with carcinoid-like features.

  • Harach HR
  • J. Clin. Pathol.
  • 1993 Feb 27

Literature context:


Abstract:

AIMS: To show that medullary carcinomas of the thyroid are morphologically indistinguishable from gut carcinoids: the value of histochemistry in their identification and differential diagnosis from metastatic carcinoid tumours to the thyroid and some follicular cell neoplasms. METHODS: 15 thyroid medullary carcinomas with features of gut carcinoids were histochemically studied for the presence of argyrophil and argentaffin granules, and calcitonin, thyroglobulin, and serotonin immunoreaction. RESULTS: Histological features of midgut (classic) carcinoids were observed in two tumours, foregut carcinoids in 12, and hindgut carcinoids in one. All tumours showed, to a greater or lesser extent, a calcitonin immunoreaction and argyrophilia. These markers were present only in a small area showing a classic pattern of thyroid medullary carcinoma in the hindgut carcinoid-like neoplasm. Argentaffin granules and serotonin immunostaining occurred in occasional cells from four foregut carcinoid-like tumours. Thyroglobulin was not expressed in all cases and amyloid stroma was expressed in three. CONCLUSIONS: In some cases a diagnosis of metastatic carcinoid tumour to the thyroid can be considered only after ruling out clinically and histochemically medullary carcinoma of the thyroid. Immunolocalisation techniques are also essential for the differentiation between medullary carcinoma and thyroid follicular cell neoplasms that resemble carcinoid tumours. It is proposed that this tumour variant to be incorporated into current classifications as another histological subtype of C cell carcinoma.

Funding information:
  • PHS HHS - HHSN272200900018C(United States)

Cholecystokinin concentrations and peptide immunoreactivity in the intact and deafferented medullary dorsal horn of the rat.

  • Jacquin MF
  • J. Comp. Neurol.
  • 1992 Dec 1

Literature context:


Abstract:

To further address the hypothesis that cholecystokinin (CCK) in the medullary dorsal horn (MDH) arises from intrinsic or higher-order neurons, CCK-8-specific radioimmunoassay (RIA) and immunohistochemical (IHC) experiments were carried out in adult rats after trigeminal tractotomy. RIA of punches from deafferented superficial layers of the MDH revealed no significant change in CCK levels vs. the control right side. In this same area, IHC revealed modest reductions in CCK, gastrin, and substance P staining. Calcitonin gene-related peptide (CGRP) staining was reduced substantially. Gastrin immunoreactive cell bodies, present normally in inner lamina II, were reduced in number. RIA and IHC methods were also used to assess MDH CCK concentrations in adult rats subjected to left infraorbital nerve section at birth. The left medulla contained significantly higher levels of CCK than the control right medulla (1.27 +/- 0.19 vs. 0.97 +/- 0.11 ng/mg protein). IHC revealed a dense band of CCK-like staining in laminae I and II ipsi- and contralateral to the lesion. Thus, neonatal deafferentation elevates medullary CCK. To determine if the neonatal lesion-induced increase in medullary CCK is due to primary afferent or higher-order reorganization, RIA and IHC experiments were run after infraorbital nerve section at birth and trigeminal tractotomy in adulthood. RIA revealed no significant change in CCK levels caudal to the tractotomy, although they were higher than control levels in 9 of 12 cases. IHC revealed modest reductions in CCK, substance P, and gastrin staining that resembled the reductions observed in tractotomy-alone cases. These data suggest that 1) most MDH CCK is of non-primary afferent origin, 2) gastrin immunoreactivity in layer II probably originates in CCK-containing cells intrinsic to layer II, the expression of which is dependent upon trigeminal primary afferent input, 3) neonatal V deafferentation induces increased CCK in the superficial MDH, reflecting reorganized intrinsic or higher-order inputs, and 4) higher-order substance P in the MDH is robust.

Funding information:
  • NINDS NIH HHS - R01 NS050437(United States)

Immunocytochemical survey of putative neurotransmitters in taste buds from Necturus maculosus.

  • Welton J
  • J. Comp. Neurol.
  • 1992 Oct 22

Literature context:


Abstract:

To investigate synaptic mechanisms in taste buds and collect information about synaptic transmission in these sensory organs, we have examined taste buds of the mudpuppy, Necturus maculosus for the presence of neurotransmitters and neuromodulators. Immunocytochemical staining at the light microscopic level revealed the presence of serotonin-like and cholecystokinin-like (CCK) immunoreactivity in basal cells in the taste bud. Nerve fibers innervating taste buds were immunoreactive for vasoactive intestinal peptide-like (VIP), substance P-like, and calcitonin gene-related peptide-like (CGRP) or compounds closely related to these substances. Immunoreactivity for tyrosine hydroxylase (TH) and choline acetyltransferase (ChAT) in the taste cells and nerve fibers was absent. These data suggest that serotonin, CCK, VIP, substance P, and CGRP are involved in synaptic transmission or neuromodulation in the peripheral organs of taste. No evidence was found for cholinergic or adrenergic mechanisms on the basis of the absence of immunocytochemical staining for key enzymes involved in these two transmitter systems.

Funding information:
  • NEI NIH HHS - EY012135(United States)

Ontogeny of substance P-, CGRP-, and VIP-containing nerve fibers in the amphibian carotid labyrinth of the bullfrog, Rana catesbeiana. An immunohistochemical study.

  • Kusakabe T
  • Cell Tissue Res.
  • 1992 Jul 2

Literature context:


Abstract:

The ontogeny of substance P, CGRP (calcitonin gene-related peptide), and VIP (vasoactive intestinal polypeptide) containing nerve fibers in the carotid labyrinth of the bullfrog, Rana catesbeiana, was examined by the peroxidase-antiperoxidase method. The time of appearance of these three peptides was different for each. First, CGRP fibers appeared in the wall of the carotid arch and external carotid arteries, and in a thin septum between these two arteries at an early stage of larval development (stage III). At stage V, substance P immunoreactive fibers appeared, and VIP fibers were detected at the early metamorphic stage (stage XXII). Up to the completion of metamorphosis, the number of these fibers remained low. From 1 to 5 weeks after metamorphosis, substance P, CGRP, and VIP fibers increased in number to varying degrees. By 8 weeks after metamorphosis, the distribution and abundance of these fibers closely resembled those of the adults. Some CGRP and VIP immunoreactive glomus cells were found at the stages immediately before and after the completion of metamorphosis. These findings suggest that substance P, CGRP, and VIP fibers during larval development and metamorphosis may be nonfunctional, and start to participate in vascular regulation only after metamorphosis. The transient CGRP and VIP in some glomus cells may be important for the development of the labyrinth, or may take part in vascular regulation through the close apposition of the glomus and smooth muscle cells (g-s connection).

Funding information:
  • NIMH NIH HHS - P50 MH106934(United States)

Immunohistochemical, morphological and functional changes in the peripheral sudomotor neuro-effector system in elderly people.

  • Abdel-Rahman TA
  • J. Auton. Nerv. Syst.
  • 1992 Jun 25

Literature context:


Abstract:

Age-related changes in the human peripheral sudomotor neuro-effector system have been investigated in six 80-year-olds and six young adults. Histochemical and immunohistochemical studies on forearm skin biopsies showed diminished vasoactive intestinal polypeptide (VIP) and calcitonin gene related peptide (CGRP)-like immunoreactivity and a virtual absence of acetylcholinesterase in the elderly sudomotor nerve endings compared to the young. Reduced size of nerve bundles and decreased density of sympathetic nerve endings adjacent to the sweat glands of old people were shown by the neuronal marker, protein gene product (PGP 9.5), and by electron microscopy. Image analysis techniques were also used to demonstrate a marked regression in secretory coil size with age. Functional decrements accompanying the neurochemical and morphological changes in the neuro-effector system were measured in ten 80-year-olds by local quantitative nicotine axon reflex responses and compared with 12 young adults. These studies demonstrate marked regressive changes in both the nerve endings and target cells in old age and appear to express a significant loss of vigour in trophic interactions.

Funding information:
  • Wellcome Trust - 091593/Z/10/Z(United Kingdom)

The co-localization of neuropeptides in the submucosa of the small intestine of normal Wistar and non-diabetic BB rats.

  • Pataky DM
  • Neuroscience
  • 1990 Nov 19

Literature context:


Abstract:

Immunocytochemical double and triple staining techniques were employed on whole mounts of the submucosal plexus from normal Wistar and non-diabetic BB rat jejunum and ileum, to determine the patterns of co-localization of vasoactive intestinal polypeptide-, peptide histidine-isoleucine-, somatostatin-, neuropeptide Y-, calcitonin gene-related peptide-, substance P-, and galanin-immunoreactive nerves. Neuropeptide Y immunoreactivity was found in 38% of submucosal plexus neurons, within the same neuronal elements as vasoactive intestinal polypeptide immunoreactivity (39% of submucosal plexus neurons) and peptide histidine-isoleucine immunoreactivity. A small population (1% of submucosal plexus neurons) containing vasoactive intestinal polypeptide- and peptide histide isoleucine-like immunoreactivity without NPY-like immunoreactivity was also observed. A significant population of fibers containing vasoactive intestinal polypeptide and galanin immunoreactivity were observed in the mucosa and submucosa, although no cell bodies were detected which contained both neuropeptides. Galanin-like immunoreactivity was seen in a small (2% of submucosal plexus neurons) population, not co-localized with any of the other neuropeptides examined. All somatostatin-immunoreactive neuronal elements (18% of submucosal plexus neurons) contained calcitonin gene-related peptide immunoreactivity, just over half of which also contained substance P immunoreactivity. An additional 25% of submucosal plexus neurons contained calcitonin gene-related peptide- without somatostatin-like immunoreactivity and 28% of submucosal plexus neurons contained substance P without somatostatin-like immunoreactivity. Some degree of co-localization was seen between calcitonin gene-related peptide- and substance P-like immunoreactivity, however, this could not be directly quantified.(ABSTRACT TRUNCATED AT 250 WORDS)

Funding information:
  • NEI NIH HHS - EY02608(United States)
  • NINDS NIH HHS - 1-R01 NS054814-05(United States)

Serotonin-, somatostatin- and chromogranin A-containing cells of the urethro-prostatic complex in the sheep. An immunocytochemical and immunofluorescent study.

  • Vittoria A
  • J. Anat.
  • 1990 Aug 9

Literature context:


Abstract:

The urethral and prostatic epithelial of the sheep contain a large number of amine- and/or peptide-producing neuroendocrine cells (NE), also called paraneurons. Four different cell types have been immunohistochemically recognised among them. The first contains the amine serotonin, the second the protein chromogranin A, the third the amine and the protein together and the fourth the hormone somatostatin. Serotonin-producing cells are elongated in shape and often show cytoplasmic dendrite-like processes directed towards the basal membrane and/or the lumen. Chromogranin A-containing cells are polymorphic and constitute the more numerous NE subpopulation. Cells containing both the bioactive substances seem to be less numerous than the chromogranin A cells and slightly more frequent than the serotonin cells. All these cell types are diffused along the whole urethro-prostatic complex and show their highest density in the collicular zone. Somatostatin-containing cells often show a unique cytoplasmic extension directed towards the basal membrane and are rare. It is supposed that the presence of serotonin in the urogenital tract is functionally correlated with the emission of urine and/or semen, while somatostatin is associated with the inhibition of local exocrine and/or endocrine secretions.

Funding information:
  • NIDDK NIH HHS - R21 DK089391(United States)

Neuronal localization of cholecystokinin mRNA in the rat brain by using in situ hybridization histochemistry.

  • Ingram SM
  • J. Comp. Neurol.
  • 1989 Sep 8

Literature context:


Abstract:

The distribution of cholecystokinin (CCK) mRNA in the rat brain was determined by means of in situ hybridization histochemistry. Our results demonstrate a widespread distribution of neurons containing CCK mRNA throughout the rat brain. Hybridization-positive neurons were distributed throughout the neocortex, olfactory bulb, claustrum, amygdala, the dentate gyrus and hippocampus proper, and several subnuclei of the thalamus and the hypothalamus. The most abundant and most heavily labeled neurons were found in the endopiriform/piriform cortex, tenia tecta, and the ventral tegmental area. The distribution of neurons positive for CCK mRNA paralleled that of CCK-like immunoreactive neurons. These results detail the distribution of CCK mRNA and clearly identify the existence of CCK-synthesizing neurons in regions such as the paraventricular and supraoptic nuclei of the hypothalamus, where the presence of CCK cell bodies was previously uncertain.

Funding information:
  • NEI NIH HHS - EY06469(United States)
  • NINDS NIH HHS - U54 NS093793(United States)

Identification and initial characterization of adipokinetic hormone-like immunoreactive peptides of rat origin.

  • Schueler PA
  • J. Neurochem.
  • 1986 Jul 23

Literature context:


Abstract:

An antiserum was raised to adipokinetic hormone (AKH), a 10-amino-acid-residue peptide found in the arthropod Locusta migratoria. The antiserum demonstrated not only immunocytochemical reaction with some other arthropod species, but also stained many areas of the rat CNS, certain islet cells of the pancreas, and some anterior pituitary cells. The pattern of staining was unlike that for any known rat neuropeptide or hormone. With the antiserum used as the detection system, HPLC and high-voltage electrophoresis yielded two peptides that were purified to homogeneity from rat hypothalamic median eminence. These peptides have unique amino acid compositions, indicating they may be heretofore unknown rat neuropeptides.

Funding information:
  • NIGMS NIH HHS - U54 GM093342(United States)
  • NINDS NIH HHS - NS-19699(United States)