Residual photosensitivity in mice lacking both rod opsin and cone photoreceptor cyclic nucleotide gated channel 3 α subunit
Residual photosensitivity in mice lacking both rod opsin and cone photoreceptor cyclic nucleotide gated channel 3 α subunit
复制标题
DOI：
10.1017/s0952523804215024
复制
发表时间：
2004-09-01
影响因子：
1.9
通讯作者：
Lucas, RJ
中科院分区：
文献类型：
--
作者：
Barnard, AR;Appleford, JM;Lucas, RJ
哺乳动物视网膜包含三类光感受器。除了视杆细胞和视锥细胞之外，视网膜神经节细胞的一个子集表达假定的感觉神经色素黑视素，其具有固有的光敏性。功能和解剖学研究表明，这些内部视网膜光感受器提供光信息的一些非图像形成的光反应，包括光诱导的生物钟和瞳孔光反射。在这里，我们采用了一种新开发的小鼠模型轴承杆和锥光转导级联（Rho（-/-）Cnga 3（-/-））的病变，以进一步研究这些非杆非锥光感受器的功能。钙成像证实了Rho（-/-）Cnga 3（-/-）小鼠中视网膜内光感受器的存在。而且。这些动物保留了瞳孔对光反射光诱导和视交叉上核中即刻早期基因c-fos的光诱导，这与先前的发现一致，即瞳孔和昼夜节律反应可以利用内部视网膜光感受器。Rho（-/-）Cnga 3（-/-）小鼠还显示视网膜的神经节细胞和（特别是）内核层中的FOS阳性细胞数量的光依赖性增加。受影响的细胞的平均数量是小鼠视网膜中黑视蛋白阳性细胞数量的数倍，这表明视网膜内这些内部视网膜光感受器的功能性细胞间连接。最后，然而。虽然我们显示野生型在光暴露时表现出心率的所有增加，但是在Rho（-/-）Cnga 3（-/-）小鼠中不存在这种反应。因此。似乎非视杆非视锥光感受器可以驱动许多。但不是全部非成像光响应。
The mammalian retina contains three classes of photoreceptor. In addition to the rods and cones, a subset of retinal ganglion cells that express the putative sensory photopigment melanopsin are intrinsically photosensitive. Functional and anatomical studies suggest that these inner retinal photoreceptors provide light information for a number of non-image-forming light responses including photoentrainment of the circadian clock and the pupil light reflex. Here, we employ a newly developed mouse model bearing lesions of both rod and cone phototransduction cascades (Rho(-/-) Cnga3(-/-)) to further examine the function of these non-rod non-cone photoreceptors. Calcium imaging confirms the presence of inner retinal photoreceptors in Rho(-/-) Cnga3(-/-) mice. Moreover. these animals retain a Pupil light reflex. photoentrainment, and light induction of the immediate early gene c-fos in the susprachiasmanic nuclei, consistent with previous findings that pupillary and circadian responses can employ inner retinal photoreceptors. Rho(-/-) Cnga3(-/-) mice also show a light-dependent increase in the number of FOS-positive cells in both the ganglion cell and (particularly) inner nuclear layers of the retina. The average number of cells affected is several times greater than the number of melanopsin-positive cells in the mouse retina, suggesting functional intercellular connections front these inner retinal photoreceptors within the retina. Finally, however. while we show that wild types exhibit ail increase in heart rate upon light exposure, this response is absent in Rho(-/-) Cnga3(-/-) mice. Thus. it seems that non-rod non-cone photoreceptors can drive many. but not all. non-image-forming light responses.