Non-canonical GABAergic Pathways in the Visual System

项目摘要 光是一个非常重要的调节生理和行为在广泛的生物体。 光信息通过视网膜神经节细胞释放的谷氨酸从视网膜传递到大脑 在超过40个脑区域中，RGC也释放肽递质。尽管 尽管所有的RGC都释放谷氨酸这一普遍的教条，但已经有迹象表明一些RGC可能是GABA能的。 然而，这些潜在的GABA能RGC的身份和功能是完全未知的。我们最近 研究结果表明，表达黑视素的一个子集，内在光敏（ip）RGCs是 GABA能这项提议将检验GABA从黑视蛋白中释放的总体假设， 表达的本征光敏（ip）RGC影响非图像形成行为。其目的是 建议将定义GABA能RGC的类型和目标及其在视觉行为中的作用， 结合小鼠遗传学、基于通道视紫红质的电路追踪、解剖学、膜片钳 电生理学和行为学。除了定位GABA能RGC的身份和功能外， 研究将开辟新的研究领域，研究抑制回路在光驱动行为中的作用， physiology.

PROJECT SUMMARY Light is a profoundly important regulator of physiology and behavior across a wide range of organisms. Light information is relayed from the retina to the brain via glutamate released from retinal ganglion cells (RGCs) at more than 40 brain regions, with some RGCs also co-releasing peptide transmitters. Despite the prevailing dogma that all RGCs release glutamate, there have been hints that some RGCs may be GABAergic. However, the identity and function of these potentially GABAergic RGCs is completely unknown. Our recent findings indicate that a subset of the melanopsin-expressing, intrinsically photosensitive (ip)RGCs are GABAergic. This proposal will test the overarching hypothesis that GABA release from the melanopsin- expressing, intrinsically photosensitive (ip)RGCs influences non-image forming behaviors. The aims of this proposal will define the types and targets of GABAergic RGCs and their role in visual behavior using a combination of mouse genetics, channelrhodopsin-based circuit tracing, anatomy, patch clamp electrophysiology, and behavior. In addition to mapping the identity and function of GABAergic RGCs, these studies will open up new areas of research into the role of inhibitory circuits in light-driven behavior and physiology.