Searching across hundreds of databases
Developing cortical GABAergic interneurons rely on genetic programs, neuronal activity, and environmental cues to construct inhibitory circuits during early postnatal development. Disruption of these events can cause long-term changes in cortical inhibition and may be involved in neurological disorders associated with inhibitory circuit dysfunction. We hypothesized that tonic glutamate signaling in the neonatal cortex contributes to, and is necessary for, the maturation of cortical interneurons. To test this hypothesis, we used mice of both sexes to quantify extracellular glutamate concentrations in the cortex during development, measure ambient glutamate-mediated activation of developing cortical interneurons, and manipulate tonic glutamate signaling using subtype-specific NMDA receptor antagonists in vitro and in vivo We report that ambient glutamate levels are high (≈100 nm) in the neonatal cortex and decrease (to ≈50 nm) during the first weeks of life, coincident with increases in astrocytic glutamate uptake. Consistent with elevated ambient glutamate, putative parvalbumin-positive interneurons in the cortex (identified using G42:GAD1-eGFP reporter mice) exhibit a transient, tonic NMDA current at the end of the first postnatal week. GluN2C/GluN2D-containing NMDA receptors mediate the majority of this current and contribute to the resting membrane potential and intrinsic properties of developing putative parvalbumin interneurons. Pharmacological blockade of GluN2C/GluN2D-containing NMDA receptors in vivo during the period of tonic interneuron activation, but not later, leads to lasting decreases in interneuron morphological complexity and causes deficits in cortical inhibition later in life. These results demonstrate that dynamic ambient glutamate signaling contributes to cortical interneuron maturation via tonic activation of GluN2C/GluN2D-containing NMDA receptors.SIGNIFICANCE STATEMENT Inhibitory GABAergic interneurons make up 20% of cortical neurons and are critical to controlling cortical network activity. Dysfunction of cortical inhibition is associated with multiple neurological disorders, including epilepsy. Establishing inhibitory cortical networks requires in utero proliferation, differentiation, and migration of immature GABAergic interneurons, and subsequent postnatal morphological maturation and circuit integration. Here, we demonstrate that ambient glutamate provides tonic activation of immature, putative parvalbumin-positive GABAergic interneurons in the neonatal cortex via high-affinity NMDA receptors. When this activation is blocked, GABAergic interneuron maturation is disrupted, and cortical networks exhibit lasting abnormal hyperexcitability. We conclude that temporally precise activation of developing cortical interneurons by ambient glutamate is critically important for establishing normal cortical inhibition.
Pubmed ID: 30846615 RIS Download
Publication data is provided by the National Library of Medicine ® and PubMed ®. Data is retrieved from PubMed ® on a weekly schedule. For terms and conditions see the National Library of Medicine Terms and Conditions.
This unknown targets Gephyrin
View all literature mentionsSoftware tool for reconstruction, visualization and analysis of neuronal processes .Fiji's framework for semi-automated tracing of neurons and other tube-like structures (blood vessels) through 3D image stacks.
View all literature mentionsSoftware package for control of automated microscopes. Cross-platform desktop application, to control motorized microscopes, scientific cameras, stages, illuminators, and other microscope accessories.
View all literature mentionsOpen source Java based image processing software program designed for scientific multidimensional images. ImageJ has been transformed to ImageJ2 application to improve data engine to be sufficient to analyze modern datasets.
View all literature mentionsImaris provides range of capabilities for working with three dimensional images. Uses flexible editing and processing functions, such as interactive surface rendering and object slicing capabilities. And output to standard TIFF, Quicktime and AVI formats. Imaris accepts virtually all image formats that are used in confocal microscopy and many of those used in wide-field image acquisition.
View all literature mentionsMulti paradigm numerical computing environment and fourth generation programming language developed by MathWorks. Allows matrix manipulations, plotting of functions and data, implementation of algorithms, creation of user interfaces, and interfacing with programs written in other languages, including C, C++, Java, Fortran and Python. Used to explore and visualize ideas and collaborate across disciplines including signal and image processing, communications, control systems, and computational finance.
View all literature mentionsMus musculus with name B6.Cg-Gt(ROSA)26Sortm9(CAG-tdTomato)Hze/J from IMSR.
View all literature mentionsMus musculus with name CB6-Tg(Gad1-EGFP)G42Zjh/J from IMSR.
View all literature mentionsMus musculus with name C57BL/6J from IMSR.
View all literature mentionsMus musculus with name B6J.Cg-Ssttm2.1(cre)Zjh/MwarJ from IMSR.
View all literature mentionsMulti paradigm numerical computing environment and fourth generation programming language developed by MathWorks. Allows matrix manipulations, plotting of functions and data, implementation of algorithms, creation of user interfaces, and interfacing with programs written in other languages, including C, C++, Java, Fortran and Python. Used to explore and visualize ideas and collaborate across disciplines including signal and image processing, communications, control systems, and computational finance.
View all literature mentionsImaris provides range of capabilities for working with three dimensional images. Uses flexible editing and processing functions, such as interactive surface rendering and object slicing capabilities. And output to standard TIFF, Quicktime and AVI formats. Imaris accepts virtually all image formats that are used in confocal microscopy and many of those used in wide-field image acquisition.
View all literature mentionsSoftware tool for reconstruction, visualization and analysis of neuronal processes .Fiji's framework for semi-automated tracing of neurons and other tube-like structures (blood vessels) through 3D image stacks.
View all literature mentionsThis unknown targets Gephyrin
View all literature mentionsOpen source Java based image processing software program designed for scientific multidimensional images. ImageJ has been transformed to ImageJ2 application to improve data engine to be sufficient to analyze modern datasets.
View all literature mentionsSoftware package for control of automated microscopes. Cross-platform desktop application, to control motorized microscopes, scientific cameras, stages, illuminators, and other microscope accessories.
View all literature mentionsThe SciCrunch Infrastructure was developed as a cooperative data platform to be used by diverse communities in making data more FAIR.
scicrunch.org
