1989 Fiscal Year Final Research Report Summary
Function and morphology of vertebrate retina
| Project/Area Number |
62480021
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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 |
動物発生・生理学
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| Research Institution | Okazaki National Research Institutes |
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Principal Investigator |
NAKA Ken-ichi National Institute for Basic Biology, 基礎生物学研究所, 教授 (90132737)
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| Co-Investigator(Kenkyū-buntansha) |
SAKAI Hiroko National Institute for Basic Biology, 基礎生物学研究所, 助手 (40132732)
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| Project Period (FY) |
1987 – 1989
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| Keywords | Neuron Network / White-noise analysis / Transfer function / シナプス |
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| Research Abstract |
We have dissected neuron network in the inner catfish retina by injection a current one neuron and by recording resulting responses from a nearby neuron. A current injected into an amacrine or a ganglion cell always produced a response from neighboring amacrine or ganglion cells chosen randomly. For neurons of similar response patterns, e.g. on-cell pair, off-cell pair or of-off cell pair, bidirectional communications exist. These communications are mutually 'excitatory', fast, and likely linear.
Signal transmission between neurons of different response-patterns was also shown to exist. This transmission is much slower and complex. For example, transmission of signal between some types of amacrine cells is bandpass with a tuning frequency of 35 Hz, and is neither excitatory nor inhibitory.
These results show that 1) amacrine and ganglion cells form an extensively coupled neuron network, 2) exclusive or specialized connections do not seem to exist in catfish retina, 3) classical notions of neural communication based on the dichotomy of excitatory and inhibitory interactions may have to be modified and 4) the neuron network in inner retina is significantly similar to some of the artificial 'neuron networks'. Responses from catfish retinal neurons do not differ much from those in other lower vertebrate retinas and the conclusions drawn here may be applicable to other retinas.
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