| Project/Area Number |
61570078
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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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 | Okazaki National Research Institutes |
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Principal Investigator |
OHTSUKA Teruya National Institute for Physiological Sciences, 生理学研究所・生体情報研究系神経情報, 助教授 (10051814)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1987: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1986: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | rod / cone / oil droplet / ribbon synapse / 視細胞 / Horseradish peroxidase / horseradish peroxidase |
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| Research Abstract |
The synaptic contacts between photoreceptors and horizontal cells in the retina of the turtle(Geoclemys)were studied.Horizontal cells were classified into three types according to their intracellularly recorded spectral responses:luminosity,biphasic chromaticity,and triphasic chromaticity horizontal cells(LHC,BHC,and THC).These cells were then iontophoretically filled with horseradish peroxidase(HRP).The various types of photoreceptors located within the dendritic field of the HRP-filled horizonal cells were identified either as rods of as one of the three chromatic types of cones;the latter were identified by the presence and colors of their oil droplets in the inner segments.The synaptic contacts between photoreceptors and labeled horizontal cells were then investigated by light and electron microscopy of serial sections on three LHCs,two BHCs,and one THC.LHCs made synaptic contacts with about 100 photoreceptors,including roads and three chromatic types of cones;two-thirds of these photoreceptors contacted the cell body and the remaining its axon terminal.BHCs contacted about 30 cones:red-, green-,and blue-sensitive cones in the ratio of 3:4:1.THC contacted 20 cones; red-and blue-sensitive cones in the ratio of 2:1.The dendritic processes of HRP-filled horizontal cells were found as the lateral element of the ribbon synaptic complexes.The present finding suggests that the responses of BHC and THC to red flashes are fed directly from red-sensitive cones in addition to the feedback pathway of cone-horizontal cell commections in the previous studies.
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