| Project/Area Number |
03454134
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Neurophysiology and muscle physiology
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| Research Institution | Kurume University |
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Principal Investigator |
NISHI Syogoro Kurume Univ.Sch.Med., Professor, 医学部, 教授 (00080557)
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| Co-Investigator(Kenkyū-buntansha) |
TANAKA Eiichiro Kurume U.Sch.Med., Instructor, 医学部, 助手 (80188284)
MIHARA Satoshi Kurume U.Sch.Med., Instructor, 医学部, 助手 (40166103)
INOKUCHI Hiroe Kurume U.Sch.Med., Asst.Prof., 医学部, 講師 (10080558)
YOSHIMURA Megumu Kurume U.Sch.Med., Asst.Prof., 医学部, 講師 (10140641)
HIGASHI Hideho Kurume U.Sch.Med., Assoc.Prof., 医学部, 助教授 (10098907)
矢野 秀樹 久留米大学, 医学部, 助手 (60210308)
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| Project Period (FY) |
1991 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥6,500,000 (Direct Cost: ¥6,500,000)
Fiscal Year 1993: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1992: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1991: ¥4,900,000 (Direct Cost: ¥4,900,000)
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| Keywords | sympathetic preganglionic neuron / fast EPSP / presynaptic inhibition / alpha_1 and alpha_2 receptor / slow EPSP and IPSP / signal transduction / serotonin / tachykinin / 緩徐シナプス電位 / ノルアドレナリン / substance P / alpha_1受容体 / alpha_2受容体 / シグナル・トランスダクション / slow EPSP / slow IPSP / tachykinins / Ca依存性Kコンダクタンス / 交感性節前ニュ-ロン / 緩徐シナプス伝達 / P物質 / マイスナ-神経叢細胞 |
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| Research Abstract |
1. Presynaptic regulation of sympathetic preganglionic neurons (SPN) : Noradrenaline (NA) inhibits the fast EPSP presynaptically This inhibiton appeared to be due to activation of alpha_2 receptors on the gultaminergic presynaptic nerve terminals that might cause hyperpolarization and/or reduction of Ca conductance of the terminal membrane.
2. The receptor and signal transduction mechanisms underlying the catecholaminergic transmission in SPNs : The alpha_1 and alpha_2 receptors on SPNs, respectively, mediate the slow EPSP and the slow IPSP.The alpha_1 receptors are endowed mainly on the dendrites and the alpha_2 receptors on the soma. The former produces the slow response via G-protein and proteinkinase C and the latter via G-protein alone.
3. The indolaminergic and peptidergic transmissions in SPNs : Both serotonin (5-HT) and tachykinins cause reduction of the Ca-dependent K conductance that results in a slow depolarization and the inhibition of the slow afterhyperpolarization of SPNs. The 5-HT action is mediated by 5-HT_2 receptors.
4. Intracellular signal transduction that mediates the slow IPSP in submucous neurons of the guinea-pig caecum : The mechanisms underlying intracellular signal transduction of the slow IPSP mediated by NA appeared to be following : i) the increased K conductance was mediated by the activation of pertussis toxin-sensitive G protein and the corresponding accumulation of intracellular Ca^<2+> released from the internal stores by IP_3. The binding of the released Ca^<2+> to calmoduline might result in an increase in potassium conductance.
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