Raymond P A, Reifler M J, Rivlin P K
Neuroscience Program, University of Michigan Medical School, Ann Arbor 48109-0616.
J Neurobiol. 1988 Jul;19(5):431-63. doi: 10.1002/neu.480190504.
This study describes regeneration of the neural retina in juvenile goldfish. The retina was destroyed with an intraocular injection of ouabain, a technique introduced by Wolburg and colleagues (Maier and Wolburg, 1979; Kurz-Isler and Wolburg, 1982). We confirmed their observation that the level of damage produced by the toxin was graded, in that neurons in the inner retinal layers were preferentially destroyed, and only in the more severely affected retinas were cells in the outer nuclear layer (i.e., photoreceptor cells) damaged. Evidence of retinal regeneration could be seen beginning about 2 weeks after the injection of ouabain. In contrast to previous studies (Maier and Wolburg, 1979), we found that regeneration took place only in those retinas in which photoreceptors had been destroyed. In cases in which the outer nuclear layer was spared, no regeneration of inner layers occurred, even after 6 months. Thymidine autoradiography was used to document the regeneration of new retinal neurons and to show that rod precursors, like other dividing cells, were not destroyed by the ouabain, but in contrast showed an increased mitotic activity. Regeneration did not proceed uniformly, but was initiated at neurogenic foci scattered across the retina. These foci consisted of clusters of dividing neuroepithelial-like cells. The evidence is consistent with the proposal that these cells were derived from rod precursors. These results imply that rod precursors are capable of a wider range of developmental fates than they normally express.
本研究描述了幼年金鱼神经视网膜的再生情况。通过眼内注射哇巴因破坏视网膜，这是沃尔堡及其同事引入的一种技术（迈尔和沃尔堡，1979年；库尔兹 - 伊斯勒和沃尔堡，1982年）。我们证实了他们的观察结果，即毒素造成的损伤程度是分级的，视网膜内层的神经元优先受到破坏，只有在受影响更严重的视网膜中，外核层（即光感受器细胞）的细胞才会受损。注射哇巴因约2周后可见视网膜再生的迹象。与先前的研究（迈尔和沃尔堡，1979年）不同，我们发现再生仅发生在光感受器已被破坏的那些视网膜中。在外核层未受影响的情况下，即使6个月后内层也不会发生再生。利用胸腺嘧啶核苷放射自显影技术记录新视网膜神经元的再生情况，并表明视杆前体细胞与其他分裂细胞一样，未被哇巴因破坏，反而显示出有丝分裂活性增加。再生并非均匀进行，而是从散布在整个视网膜上的神经源性病灶开始。这些病灶由分裂的神经上皮样细胞簇组成。证据支持这些细胞源自视杆前体细胞的观点。这些结果表明，视杆前体细胞能够产生比其正常表达的更广泛的发育命运。
