シンポジウム発表の要旨(谷藤):

皮質視覚野には脳表面に沿った水平方向の神経活動の相互作用があり、それを担う神経回路として遠位のカラムをつなぐように層に沿って長く伸びる神経結合が着目されている(long range connection)。一方、視覚野には層と層との間をつなぐ垂直方向の神経結合が密に存在し各々の神経結合もある程度の水平方向の広がりを持っている。我々は、一部の神経回路を遮断したときの視覚野の水平方向の神経興奮伝播の変化から、このような垂直方向の神経経路も水平方向の相互作用に関与していることを明らかにした。

Horizontal interaction among neurons across receptive fields or functional columns has been shown in the primary visual cortex. The long range horizontal connections extending along cortical layers and forming clustered terminals on distant functional columns provide neural basis of such horizontal interaction. On the other hand, the primary visual cortex is characterized by abundant vertical neural connections among cortical layers. We tested the possibility whether the vertical connections contribute to horizontal interaction of neurons. Optical recording of neural activity showed that there is some horizontal spread in cortical slices, and this horizontal spread disappeared when neural connections between infra- and supragranular layers were interrupted. On the other hand, interruption of horizontal connections along cortical layers did not affect horizontal spread of neural activities. This observation suggests that vertical connections as well as long range horizontal connections participate in horizontal interaction of neurons in primary visual cortex.


大脳皮質に関する研究論文のリスト:

Tanifuji M, Sugiyama T, Murase K, Horizontal propagation of excitation in rat cortical slices revealed by optical imaging. Science 266: 1057-1059, 1994.


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