| Budget Amount *help |
¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1987: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1986: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Research Abstract |
It is well-known in the monkey that lesions of area TE of inferotemporal cortex of the combined lesions of the amygdala and hippocampus result in severe impairment of visual memory.This suggests that there are functional interactions between area TE and the amygdala and hippocampus in formation of visual memory.It is unlikely,however,that the connectivities of different portions within area TE with the amygdala and hippocampus are homogeneous.The purpose of the present study is to find out more localized portion within area TE which is intimately involved in visual memory.For this,we first examined the connectivity of area TE with the amygdala,hippocampal formation and parahippocampal cortices by WGA-HRP injections into different portions within area TE.As a result,area TE had extensive reciprocal commections with the amygdala,hippocampal CA1 and parahippocampal areas.However,their strength of connections varied from one case to another.The amygdala connected strongly with'the dorsal TE area,while the hippocampal CA1 and parahippocampal cortices connected strongly with the ventral TE area.These connectivities were much stronger with the anterior half of area TE(TEa)than the posterior one(TEp). On the basis of the anatomical findings,we examined effects of lesions of the total TE(TEt)area,TEa,TEp and TEO posterior to area TE on retention and relearning of concurrent object discrimination learning which is a king of visual memory tasks.Both of retention and relearning of this learning were impaired by TEtand TEa lesions,while no impairment was seen in TEp or TEO lesioned monkeys,either.Thus,the present study indicates that the anterior TE area,which connected storongly with the amygdala and hippocampal and parahippocampal areas,is involved intimately in visual memory,while the posterior TE area is not.
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