新世界ザル（マーモセット）網膜における網膜神経節細胞の形態的・機能的多様性

Morphological and Functional Diversity of Retinal Ganglion Cells in the Common Marmoset

網膜は，出力神経細胞である網膜神経節細胞（視神経細胞）で視覚情報に応じた活動電位パターンを発生させ，脳中枢へと情報を送っている。マウスやウサギといった哺乳類の網膜神経節細胞には，形態的・機能的多様性が知られているが，今回，霊長類［新世界ザル（マーモセット）］網膜にも，方向選択性網膜神経節細胞などの多様な種類の細胞があることが，網膜組織培養法と緑色蛍光蛋白などの遺伝子導入により明らかになった。また網膜から視床を経由し視覚野に視覚情報を送るMとP経路以外の第三の経路を明らかにすることができた。

Abstract

Retinal ganglion cells are projecting neurons that send visual information from the retina to the brain. They generate different patterns of action potentials in response to different kinds of visual information. In the retinas of mammals such as mice or rabbits, there are functionally and morphologically diverse retinal ganglion cells. However, in the primate retina, midget and parasol cells are believed to be dominant, and show less diversity. In this study, we performed organotypic culture of retinas and acute gene transfection of GFPs by gene-gun. We found more diverse retinal ganglion cells, including directional selective ganglion cells, than we expected, even in the retinas of primates such as common marmosets. Further, we found a third pathway from the retina to the brain via the thalamus, in addition to the magnocellular and parvocellular pathways.