Melanopsin-dependent photoreception provides earliest light detection in the mammalian retina
Melanopsin-dependent photoreception provides earliest light detection in the mammalian retina
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DOI：
10.1016/j.cub.2005.05.053
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发表时间：
2005-06-21
期刊：
影响因子：
9.2
通讯作者：
Hankins, MW
中科院分区：
文献类型：
--
作者：
Sekaran, S;Lupi, D;Hankins, MW
背景：目前已知视觉系统由成像通路和非成像通路组成。成像途径的光接收始于视杆和视锥，而非成像途径的光接收也涉及表达光色素黑素的固有光敏视网膜神经节细胞(IpRGCs)。在小鼠视网膜中，视杆细胞和视锥感受器从出生后第10天(P10)开始变得对光敏感；然而，ipRGCs的光敏性的发展在很大程度上仍未被探索。结果：在这里，我们提供了直接的生理学证据，证明ipRGCs从出生起就对光有反应(130)，这种光敏性需要黑色素的表达。有趣的是，PO时ipRGC的数量是成人视网膜的五倍以上，反映了黑素表达细胞在发育过程中最初的过度生产。即使在130岁时，通过光诱导的Fos表达来评估，ipRGC也与视交叉上核形成了功能联系。结论：这些发现表明，在发育过程中，非成像途径早在主流成像途径之前就有了功能。
Background: The visual system is now known to be composed of image-forming and non-image-formin pathways. Photoreception for the image-forming pathway begins at the rods and cones, whereas that for the non-image-forming pathway also involves intrinsically photosensitive retinal ganglion cells (ipRGCs), which express the photopigment melanopsin. In the mouse retina, the rod and cone photoreceptors become light responsive from postnatal day 10 (P10); however, the development of photosensitivity of the ipRGCs remains largely unexplored.Results: Here, we provide direct physiological evidence that the ipRGCs are light responsive from birth (130) and that this photosensitivity requires melanopsin expression. Interestingly, the number of ipRGCs at PO is over five times that in the adult retina, reflecting an initial overproduction of melanopsin-expressing cells during development. Even at 130, the ipRGCs form functional connections with the suprachiasmatic nucleus, as assessed by light-induced Fos expression.Conclusions: The findings suggest that the non-image-forming pathway is functional long before the mainstream image-forming pathway during development.