| Project/Area Number |
60480381
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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 |
Otorhinolaryngology
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| Research Institution | HIROSHIMA UNIVERSITY |
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Principal Investigator |
HARADA Yasuo Department of Otolarungology, Hiroshima University, School of Medicine, 医学部・耳鼻咽喉科, 教授 (30033963)
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| Co-Investigator(Kenkyū-buntansha) |
YAJIN Koji Department of Otolarungology, Hiroshima University, School of Medicine, 医学部・耳鼻咽喉科, 助教授 (10136062)
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| Project Period (FY) |
1985 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1987: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1986: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Inner Ear / Scanning electron Microscopy / Patch Clamp / Synaptic Vesicle / Crista Ampullaris / patch-clamp / 酵素法 / 活動放電 / 半規管 / 感覚細胞 / 活動電位 / 単離法 / パッチ・クランプ法 / 膜電流 / 膜電位固定実験 / 膜電流固定実験 |
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| Research Abstract |
Intracellular structures of the inner ear were observed by scanning electron microscopy for the studies in synaptic vesicles. Macula, crista ampullaris and cochlear were freeze fractured and then macerated with 0.1% OsS4 solution (aldehyde-Osmium-DMSO-Osmium method). Intracellular organells such as mitochondria, endoplasmic reticulum (ER) and Golgi apparatus were demonstrated stereoscopically. Moreover, the structural characteristic of the nerve endings (efferent and afferent nervr endings) was demonstrated and the relation of synaptic bars and synaptic vesicles was morphologically shown. Especially the complicated networks of the tubular ER of a cochlear outer hair cell had an interesting structure in regard to the mechanoelectrical transduction to afferent neurons.
Physiolosically the action potential from afferent neruons of the vestibular organ of a bull frog was recorded with a glass electrode and the characteristics of the outer hair cell's membrane of guinea pig were studied using the patch clamp method. According to the pattern of the action potential there were the physiological localization of the receptors in the crista and polarity of the utricular macula. On the one hand, the single outer hair cell of a guinea pig was used in the patch clamp experiment. Membrane currents consisting of the initial inward and the following outward current were obtained by the whole cell recording of the patch clamp method. It was assumed that this inward current was caused by calcium ion which was an important ion in discharge of the chemical transmitters to the sunaptic cleft.
These results were new findings and seemed to be a stepping stone to the further studies in the inner ear study.
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