Understanding how photoswitches restore visual function in blindness

项目摘要 视网膜色素变性（RP）和年龄相关性黄斑变性（AMD）是由视网膜色素变性引起的致盲性疾病。 视杆细胞和视锥细胞退化，视觉系统的其余部分完好无损，但无法对光作出反应。一 合成的化学光开关，命名为DENAQ，可以在RP的盲小鼠模型中恢复视觉反应。 先前的研究表明，DENAQ赋予视网膜神经节细胞动作电位放电的光敏感性 (RGC)，但这是如何发生的尚不清楚。本课题的目的是阐明DENAQ的作用机制 光敏化，对于发现改进的候选药物和优化光敏化至关重要。 视力恢复的刺激策略。第一个目的是理解为什么DENAQ选择性地 光敏化来自具有死亡的视杆细胞和视锥细胞的小鼠的视网膜，而对健康的视网膜没有影响， 完整的视杆细胞和视锥细胞我们将检验变性导致DENAQ进入增强的假设。 RGC和/或增强对RGC中自发放电的离子通道的作用。第二个目标是 确定哪些RGC被DENAQ光敏化。在健康的视网膜中，一些RGC在光开始时发射，一些RGC在光开始时发射。 在偏移处，和一些在开始和偏移处。研究将确定哪些被DENAQ光敏化， 视杆细胞和视锥细胞的局部变性是否导致空间受限的RGC光敏化， 与AMD（一种局部变性疾病）特别相关。其他研究将揭示DENAQ是否 光敏作用适用于在手术视网膜切除术期间获得的组织样品中的人RGC。第三 目的是利用我们的发现来优化视力恢复。关于靶向离子通道的信息 DENAQ将能够开发更具体的光电开关。这些通道的亚细胞定位， RGC将实现更精确的空间光控制。最后，体内成像研究将揭示信号 从DENAQ处理的视网膜传输到盲小鼠的大脑，验证了DENAQ处理的视网膜的功能完整性。 视觉系统，并提供优化视网膜刺激模式的平台，以最好地再现正常 视觉反应

PROJECT SUMMARY Retinitis pigmentosa (RP) and age-related macular degeneration (AMD) are blinding diseases caused by the degeneration of rods and cones, leaving the rest of the visual system intact but unable to respond to light. A synthetic chemical photoswitch, named DENAQ, can restore visual responses in blind mouse models of RP. Previous studies showed that DENAQ imparts light-sensitivity on action potential firing in retinal ganglion cells (RGC), but how this occurs is unclear. The goal of this project is to elucidate the mechanism of DENAQ photosensitization, crucial for enabling discovery of improved drug candidates and for optimizing photo- stimulation strategies for vision restoration. The first aim is to understand why DENAQ selectively photosensitizes retinas from mice with dead rods and cones while having no effect on healthy retinas with intact rods and cones. We will test the hypothesis that degeneration leads to enhanced entry of DENAQ into RGCs and/or enhanced action on ion channels underlying spontaneous firing in RGCs. The second aim is to identify which RGCs are photosensitized by DENAQ. In the healthy retina, some RGCs fire at light onset, some at offset, and some at onset and offset. Studies will determine which are photosensitized by DENAQ, and whether local degeneration of rods and cones leads to spatially constrained RGC photosensitization, of particular relevance for AMD, a localized degenerative disease. Other studies will reveal whether DENAQ photosensitization applies to human RGCs in tissue samples obtained during surgical retinectomy. The third aim is to exploit our findings to optimize vision restoration. Information about the ion channels targeted by DENAQ will enable development of more specific photoswitches. Subcellular localization of these channels in RGCs will enable more spatially-precise photo-control. Finally imaging studies in vivo will reveal signals transmitted from the DENAQ-treated retina to the brain of blind mice, validating the functional integrity of the visual system and providing a platform for optimizing retinal stimulation patterns to best recapitulate normal visual responses.