Silveira L C, Lee B B, Yamada E S, Kremers J, Hunt D M
Departamento de Fisiologia, Universidade Federal do Pará, Belém, Brazil.
Vision Res. 1998 Nov;38(21):3329-37. doi: 10.1016/s0042-6989(97)00335-0.
Diurnal platyrrhines, both di- and trichromats, have magnocellular (M-) and parvocellular (P-) retinal ganglion cells which are morphologically very similar to those found in catarrhines. Catarrhine central P ganglion cells contact single midget bipolar cells, which contact single cones. Physiological recordings of retinal ganglion cells of dichromatic Cebus monkeys showed very similar cell properties to the catarrhine macaque, except that P ganglion cells lacked colour-opponency. We describe the presence of single-headed midget bipolar cells in the Cebus retina. These midget bipolar cells have axon terminal sizes in the same range as the dendritic tree sizes of P ganglion cells as far as 2 mm of retinal eccentricity. This result supports the view that, as in catarrhines, central P ganglion cells of platyrrhines receive input from single midget bipolar cells which in turn, receive input from single cones. This finding is consistent with the idea that a P pathway with one-to-one connectivity was present in the anthropoid ancestor before the divergence between catarrhines and platyrrhines.
昼行性阔鼻猴，包括二色视觉和三色视觉的种类，都有大细胞（M-）和小细胞（P-）视网膜神经节细胞，其形态与狭鼻猴的非常相似。狭鼻猴的中央P神经节细胞与单个侏儒双极细胞相连，而这些侏儒双极细胞又与单个视锥细胞相连。对二色视觉的僧帽猴视网膜神经节细胞的生理记录显示，其细胞特性与狭鼻猴猕猴非常相似，只是P神经节细胞缺乏颜色拮抗特性。我们描述了僧帽猴视网膜中存在单头侏儒双极细胞。这些侏儒双极细胞的轴突终末大小与P神经节细胞树突大小范围相同，直至视网膜偏心度达2毫米处。这一结果支持了这样一种观点，即与狭鼻猴一样，阔鼻猴的中央P神经节细胞接收来自单个侏儒双极细胞的输入，而这些侏儒双极细胞又依次接收来自单个视锥细胞的输入。这一发现与这样一种观点一致，即在狭鼻猴和阔鼻猴分化之前，类人猿祖先中就存在具有一对一连接的P通路。
