Burmeister D W, Dunn-Meynell A A
Department of Physiology, Cornell University Medical College, New York, NY 10021.
Brain Res. 1987 Oct 13;423(1-2):56-62. doi: 10.1016/0006-8993(87)90824-9.
When the axons of goldfish retinal ganglion cells are severed the cell bodies undergo a series of changes as the axons regenerate. These changes begin to reverse when the axons start to innervate the tectum and by 3 months after the lesion the cell bodies have nearly returned to normal. When the axons projecting to the caudal tectum were severed by a mediolateral transection of the tectum, only retinal ganglion cells in the nasal portion of the contralateral retina underwent the changes normally associated with regeneration, followed by a speedy return to normal. Because the injured fibers probably did not fully retract from the tectum, these results indicated that: (1) the complete removal of the axons from the tectal milieu was not essential for initiating the cell body changes, and (2) close proximity to the target sites would speed the recovery of the cells. When the caudal portion of the tectum was ablated the retinal ganglion cells of the nasal retina remained enlarged significantly longer than after tectal transection. During the time the cells remained enlarged the electrophysiological projection onto the remaining rostral part of the tectum revealed no significant 'compression' of the visual field. Compression of the visual field onto the rostral portion of the tectum can be accelerated if the caudal tectal ablation is accompanied by an optic nerve crush. However, under this condition the recovery of ganglion cells in the nasal retina was significantly slower than the recovery of cells in the temporal retina. This may reflect an element of topographical specificity in the regulation of the recovery of the cell body from axonal injury.
当金鱼视网膜神经节细胞的轴突被切断时，随着轴突再生，细胞体会经历一系列变化。当轴突开始支配视顶盖时，这些变化开始逆转，并且在损伤后3个月，细胞体已几乎恢复正常。当通过视顶盖的中外侧横切切断投射到尾侧视顶盖的轴突时，只有对侧视网膜鼻侧部分的视网膜神经节细胞经历了通常与再生相关的变化，随后迅速恢复正常。由于受损纤维可能并未完全从视顶盖缩回，这些结果表明：（1）从视顶盖环境中完全去除轴突对于启动细胞体变化并非必不可少，并且（2）与靶位点紧密相邻会加速细胞的恢复。当视顶盖的尾侧部分被切除时，鼻侧视网膜的视网膜神经节细胞保持增大的时间明显长于视顶盖横切后。在细胞保持增大的期间，对视顶盖剩余 Rostral 部分的电生理投射显示视野没有明显的“压缩”。如果尾侧视顶盖切除伴有视神经挤压，则视野向视顶盖 Rostral 部分的压缩可以加速。然而，在这种情况下，鼻侧视网膜中神经节细胞的恢复明显慢于颞侧视网膜中细胞的恢复。这可能反映了轴突损伤后细胞体恢复调节中的一种拓扑特异性因素。
