OPTICAL STUDIES OF PHOTORECPTOR FUNCTION

这项提议的长期目标是理解以下几点 脊椎动物视网膜光感受器更新的方面：1)为什么 感光细胞外节中的光敏盘膜需要 以如此快的速度和新陈代谢费用更换？2)是什么规定了 新圆盘合成与旧圆盘脱落维护杆之间的平衡 光感受器处于动态平衡状态？3)光感受器在 负责光感受器的圆盘组装或脱落过程 病理状态，如在光毒性反应、视网膜 超然还是营养不足？ 这项研究的具体目的是使用光学显微镜方法 结合免疫组织化学和光谱学研究 如下：1)脂质过氧化在结构和功能上起什么作用？ 随着年龄的增长，视杆细胞盘膜的功能变化？2) 细胞骨架元素和昼夜节律化学变化(褪黑素)控制吗 盘膜合成？3)是细胞骨架元件或接近 具有用于触发盘的与色素上皮相关的提示的远端盘 脱毛？4)光敏药物有什么作用，营养 视网膜缺陷性和视网膜脱离对视盘和轴向的影响 通过光学不均匀性(明暗周期)测量的位移 相关的跨轴双折射带、膜折射率带) 还是通过染料标记的盘膜的轴向运动？5)供体的年龄 对人类光感受器的光学特性有什么可观察到的影响？

The long range objectives of this proposal are to understand the following aspects of vertebrate retinal photoreceptor renewal: 1) Why do the light-sensitive disk membranes in photoreceptor outer segments need to be replaced at such a rapid rate and metabolic expense? 2) What regulates the balance between new disk synthesis an old disk shedding to maintain rod photoreceptors in a homeostatic state? 3) Are deficiencies in the processes of disk assembly or shedding responsible for photoreceptor pathological states such as those found in phototoxic responses, retinal detachment or nutritional deficiencies? Specific aims of the study are to use light microscope methods in conjunction with immunohistochemistry and spectroscopy to investigate the following: 1) What role does lipid peroxidation play in structural and functional changes found in rod cell disk membranes as they get older? 2) Do cytoskeletal elements and circadian chemical changes (melatonin) control disk membrane synethesis? 3) Are cytoskeletal elements or proximity of distal disks with the pigment epithelium relevant cues for triggering disk shedding? 4) What effects do photosensitizing drugs, nutritional deficiencies and retinal detachment have on disk assembly and axial displacement as measured by optical inhomogeneities (light-dark cycle dependent transaxial birefringence bands, membrane refractive index bands) or by axial movement of dye-labeled disk membranes? 5) Does the donor age have any observable effect upon human photoreceptor optical properties?