title: State-dependent bidirectional modification of somatic inhibition in neocortical pyramidal cells.
abstract: Cortical pyramidal neurons alter their responses to input signals depending on behavioral state. We investigated whether changes in somatic inhibition contribute to these alterations. In layer 5 pyramidal neurons of rat visual cortex, repetitive firing from a depolarized membrane potential, which typically occurs during arousal, produced long-lasting depression of somatic inhibition. In contrast, slow membrane oscillations with firing in the depolarized phase, which typically occurs during slow-wave sleep, produced long-lasting potentiation. The depression is mediated by L-type Ca2+ channels and GABA(A) receptor endocytosis, whereas potentiation is mediated by R-type Ca2+ channels and receptor exocytosis. It is likely that the direction of modification is mainly dependent on the ratio of R- and L-type Ca2+ channel activation. Furthermore, somatic inhibition was stronger in slices prepared from rats during slow-wave sleep than arousal. This bidirectional modification of somatic inhibition may alter pyramidal neuron responsiveness in accordance with behavioral state.
authors: Department of Neuroscience, Research Institute of Environmental Medicine, Nagoya University, Nagoya 464-8601, Japan. kurotani@brain.riken.jp
authors: Tohru
authors: T
authors: Kurotani
authors: Kazumasa
authors: K
authors: Yamada
authors: Yumiko
authors: Y
authors: Yoshimura
authors: Michael C
authors: MC
authors: Crair
authors: Yukio
authors: Y
authors: Komatsu
mesh_terms: D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000200:Action Potentials / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D000818:Animals; D000831:Animals, Newborn; D001640:Bicuculline / Q000031:analogs & derivatives / Q000494:pharmacology; D003712:Dendrites / Q000187:drug effects / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D004558:Electric Stimulation / Q000379:methods; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018756:GABA Antagonists / Q000494:pharmacology; D053444:Inhibitory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D009433:Neural Inhibition / Q000502:physiology*; D018408:Patch-Clamp Techniques / Q000379:methods; D017966:Pyramidal Cells / Q000166:cytology*; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013111:Spider Venoms / Q000494:pharmacology; D014793:Visual Cortex / Q000166:cytology*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
chemical_list: D018691:Excitatory Amino Acid Antagonists; D018756:GABA Antagonists; D011810:Quinoxalines; C115521:SNX 482; D013111:Spider Venoms; C017069:bicuculline methiodide; D005680:gamma-Aminobutyric Acid; C056723:FG 9041; D015763:2-Amino-5-phosphonovalerate; D001640:Bicuculline