McLoon S C, Lund R D
Exp Brain Res. 1982;45(1-2):277-84. doi: 10.1007/BF00235788.
The central retinal projections have been examined in normal chick embryos early in development to determine if a transient ipsilateral projection is present. Anterograde transport of HRP identified using tetramethyl benzidine as a chromogen and degeneration techniques were used on embryos of successive ages between 6 and 16 days of incubation to show the central distribution of the retinal axons from one eye. Besides the anticipated contralateral projection, a small projection was identified to primary visual nuclei on the side of the brain ipsilateral to the injected or lesioned eye in embryos between days 6 and 12 of incubation. A projection from the injected eye into the contralateral optic nerve was also identified in a number of embryos. By embryonic day 15 the retinal projection to the ipsilateral side of the brain and into the contralateral optic nerve had disappeared. This loss of the anomalous projections coincides with a period of substantial cell death in the retinal ganglion cell layer. It appears, therefore, that in the chick, like the rat, the ipsilateral retinofugal projection resulting from an embryonic enucleation may in part be due to retention of a normal ipsilateral projection.
在发育早期对正常鸡胚的视网膜中央投射进行了检查，以确定是否存在短暂的同侧投射。使用四甲基联苯胺作为显色剂鉴定辣根过氧化物酶（HRP）的顺行运输，并对孵化6至16天的不同年龄胚胎采用变性技术，以显示来自一只眼睛的视网膜轴突的中枢分布。除了预期的对侧投射外，在孵化第6至12天的胚胎中，还发现向注射或损伤眼同侧脑内的初级视核有一小部分投射。在一些胚胎中还发现了从注射眼到对侧视神经的投射。到胚胎第15天时，向脑同侧和对侧视神经的视网膜投射消失。这些异常投射的消失与视网膜神经节细胞层大量细胞死亡的时期相吻合。因此，在鸡中，与大鼠一样，胚胎期眼球摘除导致的同侧视网膜传出投射可能部分是由于正常同侧投射的保留。
