International Advanced Interdisciplinary Research, Tohoku University, Sendai, Japan.
PLoS One. 2009 Nov 5;4(11):e7679. doi: 10.1371/journal.pone.0007679.
Channelrhodopsin-2 (ChR2), one of the archea-type rhodopsins from green algae, is a potentially useful optogenetic tool for restoring vision in patients with photoreceptor degeneration, such as retinitis pigmentosa. If the ChR2 gene is transferred to retinal ganglion cells (RGCs), which send visual information to the brain, the RGCs may be repurposed to act as photoreceptors. In this study, by using a transgenic rat expressing ChR2 specifically in the RGCs under the regulation of a Thy-1.2 promoter, we tested the possibility that direct photoactivation of RGCs could restore effective vision. Although the contrast sensitivities of the optomotor responses of transgenic rats were similar to those observed in the wild-type rats, they were enhanced for visual stimuli of low-spatial frequency after the degeneration of native photoreceptors. This result suggests that the visual signals derived from the ChR2-expressing RGCs were reinterpreted by the brain to form behavior-related vision.
通道视紫红质 2（ChR2）是一种源自绿藻的古老视蛋白，对于恢复因光感受器变性（如色素性视网膜炎）而丧失视力的患者的视力，它是一种很有前途的光遗传学工具。如果将 ChR2 基因转移到视网膜神经节细胞（RGC），这些细胞将视觉信息发送到大脑，那么 RGC 就可以被重新用于充当光感受器。在这项研究中，我们使用了一种在 Thy-1.2 启动子调控下特异性表达 ChR2 的转基因大鼠，测试了直接光激活 RGC 以恢复有效视力的可能性。尽管转基因大鼠的光运动反应的对比敏感度与野生型大鼠相似，但在天然光感受器变性后，它们对低空间频率的视觉刺激的敏感度增强。这一结果表明，来自表达 ChR2 的 RGC 的视觉信号被大脑重新解释，形成与行为相关的视觉。
