Controlling the number of melanopsin-containing retinal ganglion cells by early light exposure
Controlling the number of melanopsin-containing retinal ganglion cells by early light exposure
复制标题
DOI：
10.1016/j.exer.2013.03.011
复制
发表时间：
2013-06-01
影响因子：
3.4
通讯作者：
Wang, Ningli
中科院分区：
文献类型：
--
作者：
Hong, Jie;Zeng, Qiang;Wang, Ningli
小百分比的视网膜神经节细胞（RGC）表达黑视素并且是固有光敏的（ipRGC）。光是否会影响ipRGC的发育尚不清楚。在大鼠视网膜中，我们发现出生后第一周的持续光照显著增加了黑视素免疫阳性ipRGC的数量。这种增加对于黑视素免疫阳性ipRGC是持久的和特异性的。BrdU标记显示在恒定的光暴露期间黑视素免疫阳性ipRGC没有增殖。从上级丘的逆行标记显示，没有其他类型的RGCs被诱导表达黑视素。只有当它与RGC发育的凋亡阶段相吻合时，光暴露才能有效地增加黑视素免疫阳性的ipRGC。然而，每天玻璃体内注射河豚毒素，阻断动作电位，取消了光诱导的黑视素免疫阳性ipRGCs的增加。这些发现表明，早期光暴露可以通过依赖于内在光敏尖峰活性的过程增加黑视素免疫阳性ipRGC的数量。此外，黑视素免疫阳性ipRGC的增加可能由ipRGC中的细胞凋亡抑制或黑视素的表达增强诱导。(C)2013爱思唯尔有限公司保留所有权利。
A small percentage of retinal ganglion cells (RGCs) express melanopsin and are intrinsically photosensitive (ipRGCs). Whether light can affect the development of ipRGCs is not clear. In the rat retina, we found constant light exposure during the first postnatal week significantly increased the number of melanopsin immunopositive ipRGCs. This increase was durable and specific for melanopsin immunopositive ipRGCs. BrdU labeling showed no proliferation of the melanopsin immunopositive ipRGCs during constant light exposure. Retrograde labeling from the superior colliculus showed that no other types of RGCs were induced to express melanopsin. Light exposure was effective in increasing melanopsin immunopositive ipRGCs only when it coincided with the apoptotic phase of RGC development. However, daily intravitreous injection of tetrodotoxin, blocking action potentials, abolished the light induced increase of melanopsin immunopositive ipRGCs. These findings indicate that early light exposure can increase the number of melanopsin immunopositive ipRGCs through a process dependent on intrinsic photosensitive spiking activity. Furthermore, the increase of melanopsin immunopositive ipRGCs is potentially induced by apoptosis suppression in ipRGCs or enhanced expression of melanopsin. (C) 2013 Elsevier Ltd. All rights reserved.