Hankin M H, Hoover F, Goldman D
Department of Anatomy, Medical College of Ohio, Toledo.
J Neurobiol. 1993 Aug;24(8):1099-110. doi: 10.1002/neu.480240808.
Recent studies of optic nerve regeneration in goldfish have indicated that the optic tectum plays an important role in modulating the induction of nicotinic acetylcholine receptor (nAChR) gene expression in regenerating retinal ganglion cells (Heiber, Agranoff, and Goldman, 1992, J. Neurochem. 58:1009-1015). These observations suggest that induction of these genes is regulated by brain target regions. The appearance of nAChR mRNA in the developing rat retina coincides with a time when ganglion cells are sending axons to their brain targets (Hoover and Goldman, 1992, Exp. Eye Res. 54:561-571). Might a mechanism similar to that seen during goldfish optic nerve regeneration also mediate induction of nAChR gene expression during development of the mammalian retina? This possibility was tested by either transplanting embryonic rat retina to different brain regions, or explanting it to organ culture and assaying for nAChR gene expression. These studies showed that induction of the nAChR genes in developing rat retina is independent of the environment in which the retina develops. These results indicate that either the retinal microenvironment or a signal intrinsic to the retinal ganglion cell is responsible for this induction.
最近对金鱼视神经再生的研究表明，视顶盖在调节再生视网膜神经节细胞中烟碱型乙酰胆碱受体（nAChR）基因表达的诱导过程中起重要作用（海伯、阿格拉诺夫和戈德曼，1992年，《神经化学杂志》58:1009 - 1015）。这些观察结果表明，这些基因的诱导受脑靶区调控。在发育中的大鼠视网膜中，nAChR mRNA的出现与神经节细胞向其脑靶区发送轴突的时间一致（胡佛和戈德曼，1992年，《实验眼研究》54:561 - 571）。在哺乳动物视网膜发育过程中，是否也存在一种类似于金鱼视神经再生过程中所见的机制来介导nAChR基因表达的诱导呢？通过将胚胎大鼠视网膜移植到不同脑区，或将其外植到器官培养中并检测nAChR基因表达，对这种可能性进行了测试。这些研究表明，发育中大鼠视网膜中nAChR基因的诱导与视网膜发育的环境无关。这些结果表明，要么是视网膜微环境，要么是视网膜神经节细胞内在的信号负责这种诱导。
