タケトウ　メグミ   TAKETOU MEGUMI   武藤　恵    所属   関西医科大学  生理学講座    職種   講師
言語種別	英語
発表タイトル	Changes of spontaneous GABAergic currents after increasing pre- and post-synaptic activities in rat hippocampus.
会議名	第90回日本生理学会大会
学会区分	全国規模の学会
発表形式	ポスター掲示
講演区分	一般
発表者・共同発表者	◎Taketo M., Matsuda H.
発表年月日	2013/03
開催地 （都市, 国名）	東京
学会抄録	The Journal of Physiological Sciences 63(Supplement 1),S127 2013
概要	GABAA receptor-mediated inhibitory postsynaptic currents (IPSCs) modify excitatory synaptic transmission by altering the activity of principal neurons. The plasticity of the inhibitory synapses has not been well characterized, comparing with that of the excitatory one. Postsynaptic depolarization-induced changes of GABAAergic synaptic transmission have been reported, but both facilitation and inhibition were observed, and mechanisms of the plasticity have not been elucidated. In the present experiments, effect of the postsynaptic depolarization on spontaneous GABAAergic synaptic transmission was examined in acute slices of neonatal rat hippocampus. Using whole cell patch-clamp recording method, spontaneous GABAAergic IPSCs (sIPSCs) were recorded from CA3 neurons. Postsynaptic depolarization alone did not cause marked alteration of the frequency or amplitude of sIPSCs. Facilitation of the transmitter release by presynaptic depolarization increased frequency of the sIPSCs. Simultaneous activation of presynaptic and postsynaptic neurons, however, induced transient inhibition of the frequency of the sIPSCs. Though specific agonist of metabotropic glutamate receptors exogenously applied during postsynaptic depolarization did not mimic the inhibition of the sIPSCs, antagonists of the receptors partially suppressed the inhibition caused by the simultaneous pre- and post-synaptic stimulation. These results suggest that postsynaptic depolarization and simultaneous facilitation of presynaptic release of glutamate transiently inhibited the sIPSCs.