title: Parallel regulation of feedforward inhibition and excitation during whisker map plasticity.
abstract: Sensory experience drives robust plasticity of sensory maps in cerebral cortex, but the role of inhibitory circuits in this process is not fully understood. We show that classical deprivation-induced whisker map plasticity in layer 2/3 (L2/3) of rat somatosensory (S1) cortex involves robust weakening of L4-L2/3 feedforward inhibition. This weakening was caused by reduced L4 excitation onto L2/3 fast-spiking (FS) interneurons, which mediate sensitive feedforward inhibition and was partially offset by strengthening of unitary FS to L2/3 pyramidal cell synapses. Weakening of feedforward inhibition paralleled the known weakening of feedforward excitation. As a result, mean excitation-inhibition balance and timing onto L2/3 pyramidal cells were preserved. Thus, reduced feedforward inhibition is a covert compensatory process that can maintain excitatory-inhibitory balance during classical deprivation-induced Hebbian map plasticity.
authors.affiliation: Neuroscience Ph.D. Program, University of California, San Diego, La Jolla, CA 92093, USA.
authors.forename: David R C
authors.initials: DR
authors.lastname: House
authors.forename: Justin
authors.initials: J
authors.lastname: Elstrott
authors.forename: Eileen
authors.initials: E
authors.lastname: Koh
authors.forename: Jason
authors.initials: J
authors.lastname: Chung
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Feldman
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D055592:Biophysical Phenomena / Q000187:drug effects; D001703:Biophysics; D001931:Brain Mapping; D004558:Electric Stimulation; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D066298:In Vitro Techniques; D053444:Inhibitory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D009415:Nerve Net / Q000187:drug effects / Q000502:physiology; D009433:Neural Inhibition / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D018408:Patch-Clamp Techniques; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D020318:Rats, Long-Evans; D012683:Sensory Deprivation / Q000502:physiology; D013003:Somatosensory Cortex / Q000166:cytology*; D013997:Time Factors; D014738:Vibrissae / Q000294:innervation*
chemical_list: D018691:Excitatory Amino Acid Antagonists; D011810:Quinoxalines; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline