RUI: Pigment Granule Dispersion in Teleost Retinal Pigment Epithelium: Cholinergic Mechanisms

这项拟议的研究着眼于光线照射到眼睛时会发生什么。研究将研究眼睛适应不断变化的光照水平时会发生什么，以及这些信息是如何在视网膜和视网膜色素上皮(RPE)之间传递的。它将聚焦于视网膜用来与RPE通信的微小化学信使。RPE是位于视网膜旁边的一层组织。研究人员将使用鱼眼作为这些研究的组织来源。与人眼不同，鱼眼的瞳孔直径是固定的。鱼不会像人类那样通过扩大或缩小瞳孔来适应光线的变化。取而代之的是，他们重新排列他们的感光器和RPE中的色素颗粒，以获得适量的光到光感受器、视杆或视锥，最适合这项工作。在光线下，RPE中的色素颗粒展开成指状延伸，与视杆和视锥交织在一起。这些重排让RPE遮挡了专门用于夜视的杆状感光器，同时仍允许锥形感光器、亮光和彩色视觉专家探测光。这项研究将检查乙酰胆碱通过哪些受体工作，乙酰胆碱是一种微小的化学信使。受体就像细胞表面的小触角，它们探测环境中的特定化学物质。乙酰胆碱有许多不同类型的受体，每种受体都检测乙酰胆碱，但每种受体对细胞内的分子信号有不同的影响。这项研究将使用模拟或阻断乙酰胆碱的化学物质来找出哪种类型的受体参与了色素的分散。这项研究将阐明一种新的光适应信号通路，加强对眼睛工作原理的理解。

The proposed research looks at what happens when light hits the eye.Research will examine what happens when the eye adjusts to changing lightlevels and how that information is transmitted between the retina and theretinal pigment epithelium (RPE). It will zero in on tiny chemicalmessengers used by the retina to communicate with the RPE. The RPE is athin layer of tissue located next to the retina.The researchers will use fish eyes as a source of tissue for these studies.Unlike human eyes, fish eyes have pupils of fixed diameter. Fish don'tadjust to changing light by dilating or constricting their pupils the waypeople do. Instead they rearrange their light-sensitive photoreceptors andthe pigment granules in the RPE to get just the right amount of light to thephotoreceptors, rods or cones, best suited for the job. In the light,pigment granules in the RPE spread out into finger-like extensions thatinterlace with the rods and cones. These rearrangements let the RPE shadethe rod photoreceptors, which are specialized for night vision, while stillpermitting the cone photoreceptors, bright light and color visionspecialists, to detect light.This study will examine the receptors through which acetylcholine, one ofthe tiny chemical messengers, operates. Receptors are like little antennaefound on the surface of cells, and they detect specific chemicals in theirenvironment. There are many different types of receptors for acetylcholine.Each detects acetylcholine, but each has a different effect on molecularsignals inside the cell. This study will use chemicals that either mimic orblock acetylcholine to figure out what type of receptor is involved inpigment dispersion. This research will illuminate a novel signaling pathwayfor light adaptation, enhancing understanding of how the eye works.