Thompson I D, Morgan J E, Henderson Z
University Laboratory of Physiology, Oxford, UK.
Eur J Neurosci. 1993 Apr 1;5(4):357-67. doi: 10.1111/j.1460-9568.1993.tb00503.x.
Anterograde and retrograde tracing techniques were used to examine the effects of removing one eye at birth on the remaining uncrossed retinal pathway in adult ferrets. After enucleation, the adult number of labelled ganglion cells projecting ipsilaterally changed from an average of 6068 in normal pigmented ferrets to an average of 7813 (29% increase) in pigmented enucleates. The change in albino ferrets was from 1455 in normals to 2319 in enucleates (59% increase). Labelled cells scattered across nasal retina accounted for over half the increase in the uncrossed population. After neonatal enucleation, the volume of lateral geniculate nucleus occupied by the uncrossed projection increased substantially: five-fold in pigmented animals and 20-fold in albinos. These results suggest that neonatal removal of one eye has a greater effect on the distribution of uncrossed terminals than on the survival of uncrossed ganglion cells. There was also an increase in the total number of axons in the surviving optic nerve of both pigmented and albino ferrets (93,000 in enucleates compared with 79,000 in normal animals), which cannot be simply explained as a disruption of binocular competition.
采用顺行和逆行追踪技术,研究出生时摘除一只眼睛对成年雪貂剩余未交叉视网膜通路的影响。摘除眼球后,成年色素沉着雪貂同侧投射的标记神经节细胞数量从正常的平均6068个变为摘除眼球后的平均7813个(增加29%)。白化雪貂的变化则从正常的1455个变为摘除眼球后的2319个(增加59%)。未交叉群体增加量的一半以上是由分布在鼻侧视网膜的标记细胞造成的。新生期摘除眼球后,未交叉投射所占据的外侧膝状体核体积大幅增加:色素沉着动物增加了5倍,白化动物增加了20倍。这些结果表明,新生期摘除一只眼睛对未交叉终末的分布影响大于对未交叉神经节细胞存活的影响。色素沉着和白化雪貂存活的视神经中轴突总数也有所增加(摘除眼球的雪貂为93,000个,正常动物为79,000个),这不能简单地解释为双眼竞争的破坏。