Project/Area Number |
05452404
|
Research Category |
Grant-in-Aid for General Scientific Research (B)
|
Allocation Type | Single-year Grants |
Research Field |
Neuroscience in general
|
Research Institution | Kyushu Institute of Technology |
Principal Investigator |
YASUI Syozo Kyushu Inst.of Tech., Faculty of Computer Science and Systems Engineering, Professor, 情報工学部, 教授 (50132741)
|
Co-Investigator(Kenkyū-buntansha) |
FURUKAWA Tetsuo Kyushu Inst.of Tech., Faculty of Computer Science and Systems Engineering, Resea, 情報工学部, 助手 (50219101)
YAGI Tetsuya Kyushu Inst.of Tech., Faculty of Computer Science and Systems Engineering, Assoc, 情報工学部, 助教授 (50183976)
NIIJIMA Koichi Kyushu Ins.of Tech., Faculty of Computer Science and Systems Engineering, Profes, 情報工学部, 教授 (30047881)
|
Project Period (FY) |
1993 – 1994
|
Project Status |
Completed (Fiscal Year 1994)
|
Budget Amount *help |
¥5,400,000 (Direct Cost: ¥5,400,000)
Fiscal Year 1994: ¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1993: ¥3,200,000 (Direct Cost: ¥3,200,000)
|
Keywords | Retina / Horizontal Cell / Synapse / Glutamate / Neural Network / Data Compression-Recovery / Plasticity / NO / 情報圧縮 / 情報復元 |
Research Abstract |
Physiological experiments as well as computational studies were conducted to explore certain aspects of the neural plasticity. Due to the lack of space, this report only describes our results concerned with synaptic plasticity mechanisms in the vertebrate retina which morphogenetically is a part of the brain. Thus, we have established that the synapse from short-lambda (wavelength) sensitive cones to H1 type horizontal cells (H1 HCs) is different from the excitatory (sign-conserving) synapse mediating the long-lambda visual signal transmission, althogh both synapses presumablly use L-glutamate as the neurotransmitter ; the short-lambda synapse is sigh-inverting and conductance-decreasing with APB as an agonist, and the synapse is metabotropic with cGMP as the second messenger. Furthermore, No (nitric oxide) is involved in the molecular mechanism, by facilitating the cGMP production when the retina is light adapted. This explains the fact that the short-lambda synapse is dormant during dark adaptation. In fact, light adaptaion and No have the same effects on H1 HCs in sharpening the spectral sensitivity curve and increasing the receptive field size for red than blue lights. These observations were succesfully accounted for by a cable theory model incorporating the polarity-inverting and conductance-decreasing properties of the short-lambda synapse.
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