المؤلفون: Bidisha Chattopadhyaya, Graziella Di Cristo, Hiroyuki Higashiyama, Graham Knott, Sandra Kuhlman, Egbert Welker, Z. Josh Huang

مصطلحات موضوعية: Biological Sciences not elsewhere classified, Action Potentials, Animals, Chromosomes, Artificial, Bacterial, DNA Repair, Glutamate Decarboxylase, Green Fluorescent Proteins, Interneurons, Isoenzymes, Mice, Transgenic, Neural Inhibition, Neuronal Plasticity, Presynaptic Terminals, Pyramidal Cells, Recombinant Fusion Proteins, Sensory Deprivation, Synapses, Tetrodotoxin, Time Factors, Tissue Culture Techniques, Vision, Ocular, Visual Cortex, gamma-Aminobutyric Acid

الوصف: The neocortical GABAergic network consists of diverse interneuron cell types that display distinct physiological properties and target their innervations to subcellular compartments of principal neurons. Inhibition directed toward the soma and proximal dendrites is crucial in regulating the output of pyramidal neurons, but the development of perisomatic innervation is poorly understood because of the lack of specific synaptic markers. In the primary visual cortex, for example, it is unknown whether, and to what extent, the formation and maturation of perisomatic synapses are intrinsic to cortical circuits or are regulated by sensory experience. Using bacterial artificial chromosome transgenic mice that label a defined class of perisomatic synapses with green fluorescent protein, here we show that perisomatic innervation developed during a protracted postnatal period after eye opening. Maturation of perisomatic innervation was significantly retarded by visual deprivation during the third, but not the fifth, postnatal week, implicating an important role for sensory input. To examine the role of cortical intrinsic mechanisms, we developed a method to visualize perisomatic synapses from single basket interneurons in cortical organotypic cultures. Characteristic perisomatic synapses formed through a stereotyped process, involving the extension of distinct terminal branches and proliferation of perisomatic boutons. Neuronal spiking in organotypic cultures was necessary for the proliferation of boutons and the extension, but not the maintenance, of terminal branches. Together, our results suggest that although the formation of perisomatic synapses is intrinsic to the cortex, visual experience can influence the maturation and pattern of perisomatic innervation during a postnatal critical period by modulating the level of neural activity within cortical circuits.

العلاقة: https://figshare.com/articles/Experience_and_activity-dependent_maturation_of_perisomatic_GABAergic_innervation_in_primary_visual_cortex_during_a_postnatal_critical_period_/6098585Test

الإتاحة: https://doi.org/10.1184/r1/6098585.v1Test
https://figshare.com/articles/Experience_and_activity-dependent_maturation_of_perisomatic_GABAergic_innervation_in_primary_visual_cortex_during_a_postnatal_critical_period_/6098585Test

المؤلفون: Aryn Gittis, Sascha du Lac

مصطلحات موضوعية: Biological Sciences not elsewhere classified, Action Potentials, Anesthetics, Local, Animals, Newborn, Calcium, Dose-Response Relationship, Radiation, Electric Stimulation, Luminescent Proteins, Mice, Inbred C57BL, Inbred ICR, Transgenic, Neurons, Patch-Clamp Techniques, Peptides, Potassium Channel Blockers, Potassium Channels, Tetraethylammonium, Tetrodotoxin, Vestibular Nuclei, gamma-Aminobutyric Acid

الوصف: Neural circuits are composed of diverse cell types, the firing properties of which reflect their intrinsic ionic currents. GABAergic and non-GABAergic neurons in the medial vestibular nuclei, identified in GIN and YFP-16 lines of transgenic mice, respectively, exhibit different firing properties in brain slices. The intrinsic ionic currents of these cell types were investigated in acutely dissociated neurons from 3- to 4-wk-old mice, where differences in spontaneous firing and action potential parameters observed in slice preparations are preserved. Both GIN and YFP-16 neurons express a combination of four major outward currents: Ca(2+)-dependent K(+) currents (I(KCa)), 1 mM TEA-sensitive delayed rectifier K(+) currents (I(1TEA)), 10 mM TEA-sensitive delayed rectifier K(+) currents (I(10TEA)), and A-type K(+) currents (I(A)). The balance of these currents varied across cells, with GIN neurons tending to express proportionately more I(KCa) and I(A), and YFP-16 neurons tending to express proportionately more I(1TEA) and I(10TEA). Correlations in charge densities suggested that several currents were coregulated. Variations in the kinetics and density of I(1TEA) could account for differences in repolarization rates observed both within and between cell types. These data indicate that diversity in the firing properties of GABAergic and non-GABAergic vestibular nucleus neurons arises from graded differences in the balance and kinetics of ionic currents.

العلاقة: https://figshare.com/articles/Firing_properties_of_GABAergic_versus_non-GABAergic_vestibular_nucleus_neurons_conferred_by_a_differential_balance_of_potassium_currents_/6098981Test

الإتاحة: https://doi.org/10.1184/r1/6098981.v1Test
https://figshare.com/articles/Firing_properties_of_GABAergic_versus_non-GABAergic_vestibular_nucleus_neurons_conferred_by_a_differential_balance_of_potassium_currents_/6098981Test

المؤلفون: Graziella Di Cristo, Bidisha Chattopadhyaya, Sandra Kuhlman, Yu Fu, Marie-Claude Bélanger, Cai Zhi Wu, Urs Rutishauser, Lamberto Maffei, Z. Josh Huang

مصطلحات موضوعية: Biological Sciences not elsewhere classified, Age Factors, Analysis of Variance, Anesthetics, Local, Animals, Newborn, Critical Period (Psychology), Evoked Potentials, Visual, Gene Expression Regulation, Developmental, Glutamate Decarboxylase, Glycoside Hydrolases, Green Fluorescent Proteins, Mice, Neural Cell Adhesion Molecules, Neural Inhibition, Neuronal Plasticity, Photic Stimulation, Sensory Deprivation, Sialic Acids, Tetrodotoxin, Visual Cortex, Visual Pathways, gamma-Aminobutyric Acid

الوصف: Functional maturation of GABAergic innervation in the developing visual cortex is regulated by neural activity and sensory inputs and in turn influences the critical period of ocular dominance plasticity. Here we show that polysialic acid (PSA), presented by the neural cell adhesion molecule, has a role in the maturation of GABAergic innervation and ocular dominance plasticity. Concentrations of PSA significantly decline shortly after eye opening in the adolescent mouse visual cortex; this decline is hindered by visual deprivation. The developmental and activity-dependent regulation of PSA expression is inversely correlated with the maturation of GABAergic innervation. Premature removal of PSA in visual cortex results in precocious maturation of perisomatic innervation by basket interneurons, enhanced inhibitory synaptic transmission, and earlier onset of ocular dominance plasticity. The developmental and activity-dependent decline of PSA expression therefore regulates the timing of the maturation of GABAergic inhibition and the onset of ocular dominance plasticity.

العلاقة: https://figshare.com/articles/Activity-dependent_PSA_expression_regulates_inhibitory_maturation_and_onset_of_critical_period_plasticity_/6097184Test

الإتاحة: https://doi.org/10.1184/r1/6097184.v1Test
https://figshare.com/articles/Activity-dependent_PSA_expression_regulates_inhibitory_maturation_and_onset_of_critical_period_plasticity_/6097184Test