Barrel cortex critical period plasticity is independent of changes in NMDA receptor subunit composition.
The regulation of NMDA receptor (NMDAR) subunit composition and expression during development is thought to control the process of thalamocortical afferent innervation, segregation, and plasticity. Thalamocortical synaptic plasticity in the mouse is dependent on NMDARs containing the NR2B subunit, which are the dominant form during the "critical period" window for plasticity. Near the end of the critical period there is a gradual increase in the contribution of NR2A subunits that happens in parallel to changes in NMDAR-mediated current kinetics. However, no extension of the critical period occurs in NR2A knockout mice, despite the fact that NMDA subunit composition and current kinetics remain immature past the end of the critical period. These data suggest that regulation of NMDAR subunit composition is not essential for closing the critical period plasticity window in mouse somatosensory barrel cortex.
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Division of Neuroscience and Program in Developmental Biology, One Baylor Plaza, S-603, Baylor College of Medicine, Houston, TX 77030, USA.
Gonzalez
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Crair
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D000818:Animals; D001931:Brain Mapping; D003423:Critical Period, Psychological; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D017774:Long-Term Potentiation / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009473:Neuronal Plasticity / Q000502:physiology*; D010880:Piperidines / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology; D018091:Receptors, AMPA / Q000235:genetics / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000235:genetics* / Q000378:metabolism; D013003:Somatosensory Cortex / Q000254:growth & development* / Q000502:physiology*; D013569:Synapses / Q000502:physiology; D013788:Thalamus / Q000254:growth & development / Q000502:physiology
D018691:Excitatory Amino Acid Antagonists; D010880:Piperidines; D011810:Quinoxalines; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; C121001:NR2B NMDA receptor; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; C010739:ifenprodil