Map formation in the developing Xenopus retinotectal system: an examination of ganglion cell terminal arborizations
Map formation in the developing Xenopus retinotectal system: an examination of ganglion cell terminal arborizations
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爪蟾视网膜顶盖系统发育中的地图形成：神经节细胞末端树枝化的检查
DOI：
10.1523/jneurosci.05-12-03228.1985
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
R. Murphey
中科院分区：
文献类型：
--
作者：
D. Sakaguchi;R. Murphey
通过细胞外注射钴到非洲爪蟾胚胎和蝌蚪的视网膜中，对视网膜神经节细胞的单个轴突进行了染色。最早到达中脑的视网膜轴突的轴突末梢通常外观简单，通常终止于生长锥，并终止于与其在眼睛中的位置相适应的顶盖区域。因此，在复杂的轴突乔木的加工之前，在投影的发展（阶段37至39）中非常早地存在地形投影。视网膜轴突开始获得更成熟的功能，体现了终端乔木的阐述，由阶段39。大多数神经节细胞的乔木被拉长的喙尾尺寸在早期幼虫的生活（阶段40至45），覆盖了很大一部分的顶盖神经。在中期幼虫阶段（阶段46至50），乔木覆盖的顶盖神经鞘的比例相对较小.这种变化的定量分析表明，明显减少的乔木的大小，相对于顶盖，是由于快速增长的顶盖neurology，而不是由于最初弥漫乔木回缩。因此，在发育过程中轴突乔木靶向的细化是与再生过程中所见不同的现象。
Single axonal arbors of retinal ganglion cells have been stained by injecting cobalt extracellularly into the retinae of Xenopus embryos and tadpoles. The axonal endings of the earliest retinal axons to arrive in the midbrain were usually simple in appearance, often ended in growth cones, and terminated in tectal regions appropriate to their location in the eye. Thus, a topographic projection exists very early in the development (stages 37 to 39) of the projection, before the elaboration of complex axonal arbors. Retinal axons began acquiring more mature features, exemplified by the elaboration of terminal arbors, by stage 39. The arbors of most ganglion cells were elongated in the rostral-to-caudal dimension during early larval life (stages 40 to 45) and covered a large portion of tectal neuropil. During mid- larval stages (stages 46 to 50), arbors covered a relatively smaller proportion of the tectal neuropil. A quantitative analysis of this change suggests that the apparent decrease in size of the arbors, with respect to the tectum, is due to rapid growth of tectal neuropil and not due to retraction of an initially diffuse arbor. Thus, the refinement in targeting of axonal arbors during development is a phenomenon distinct from that seen during regeneration.