Reye Peter, Sullivan Robert, Pow David V
Department of Physiology and Pharmacology, School of Biomedical Sciences, University of Queensland, Brisbane, Queensland 4072, Australia.
J Comp Neurol. 2002 Jun 10;447(4):323-30. doi: 10.1002/cne.10218.
The distributions of a carboxyl terminal splice variant of the glutamate transporter GLT-1, referred to as GLT-1B, and the carboxyl terminus of the originally described variant of GLT-1, referred to hereafter as GLT-1 alpha, were examined using specific antisera. GLT-1B was present in the retina at very early developmental stages. Labelling was demonstrable at embryonic day 14, and strong labelling was evident by embryonic day 18. Such labelling was initially restricted to populations of cone photoreceptors, the processes of which extended through the entire thickness of the retina and appeared to make contact with the retinal ganglion cells. During postnatal development the GLT-1B-positive photoreceptor processes retracted to form the outer plexiform layer, and around postnatal day 7, GLT-1B-immunoreactive bipolar cells appeared. The pattern of labelling of bipolar cell processes within the inner plexiform layer changed during postnatal development. Two strata of strongly immunoreactive terminals were initially evident in the inner plexiform layer, but by adulthood these two bands were no longer evident and labelling was restricted to the somata and processes (but not synaptic terminals) of the bipolar cells, as well as the somata, processes, and terminals of cone photoreceptors. By contrast, GLT-1 alpha appeared late in postnatal development and was restricted mainly to a population of amacrine cells, although transient labelling was also associated with punctate elements in the outer plexiform layer, which may represent photoreceptor terminals.
使用特异性抗血清检测了谷氨酸转运体GLT-1的一种羧基末端剪接变体（称为GLT-1B）以及最初描述的GLT-1变体（以下称为GLT-1α）的羧基末端的分布情况。GLT-1B在视网膜发育的非常早期阶段就已存在。在胚胎第14天可检测到标记，到胚胎第18天可见强标记。这种标记最初局限于视锥光感受器群体，其突起贯穿视网膜的整个厚度，并似乎与视网膜神经节细胞接触。在出生后发育过程中，GLT-1B阳性的光感受器突起缩回形成外网状层，在出生后第7天左右，出现了GLT-1B免疫反应性双极细胞。出生后发育过程中，双极细胞突起在内网状层的标记模式发生了变化。在内网状层最初可见两层强免疫反应性终末，但到成年时这两条带不再明显，标记局限于双极细胞的胞体和突起（但不包括突触终末），以及视锥光感受器的胞体、突起和终末。相比之下，GLT-1α在出生后发育后期出现，主要局限于一群无长突细胞，尽管短暂标记也与外网状层中的点状成分相关，这些点状成分可能代表光感受器终末。
