Synaptic ribbons plasticity and visual sensitivity in larval zebrafish

斑马鱼幼虫突触带可塑性和视觉敏感性

• 批准号: 7608775
• 负责人: FARIDA EMRAN
• 金额: $ 5.34万
• 依托单位: HARVARD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-12-01 至 2010-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7608775
• 关键词: Affect; Age; Antibodies; Behavior; Behavioral; Behavioral Assay; Biological Models; Cells; Circadian Rhythms; Disease; Electron Microscopy; Electrons; Electroretinography; Exhibits; Eye; Eye Movements; Fertilization; Fishes; Histocytochemistry; Immunoelectron Microscopy; Immunohistochemistry; Light; Lighting; Modification; Photoreceptors; Physiological; Presynaptic Terminals; Process; Property; Proteins; Reflex action; Retina; Retinal; Retinal Cone; Role; Structure; Testing; Time; Vision; Visual; Zebrafish; behavior test; ganglion cell; light intensity; public health relevance; research study; response; ribbon synapse; vision development; visual motor

DESCRIPTION (provided by applicant): Studies in several species have shown that a number of visual phenomena are regulated by circadian mechanisms. For example, synaptic ribbons in photoreceptor terminals in larval zebrafish undergo dramatic diurnal alterations. The ribbons are very prominent during day, but are almost completely absent at night. The implications of this circadian driven process on visual function are not well understood. The proposed experiments are aimed at investigating how plasticity of synaptic ribbons in the eye relates to visual responsiveness in larval zebrafish. Preliminary studies show that larval fish at 5 days of age have normal electroretinograms (ERGs) during the day, but fail to respond to illumination at night. Two behavioral tests, the optokinetic response (OKR) and the visual-motor response (VMR), indicate that fluctuations in visual responsiveness in the day and night are not only profound in larval zebrafish, but that vision may be completely lost at night. In Specific Aim 1, I will determine how the changes in ERG and visual behavioral sensitivity alter as a function of time of day and light exposure in larval zebrafish. Single-unit and ERG recordings will be used to determine the changes in the functional properties of retinal cells in the inner and outer retina. The OKR and the VMR tests will be used to determine how time of day and light exposure affects visual responsiveness and behavior of zebrafish. In Specific Aim 2, I will characterize and quantitate changes in ribbon structure in the retina under physiological conditions as well as under various light and dark conditions. The structural changes of synaptic ribbons will be studied by electron microscopy or immunohistochemistry using antibodies against synaptic ribbon proteins. PUBLIC HEALTH RELEVANCE Zebrafish have emerged as a powerful model system to study processes underlying visual system development and differentiation. Ultrastructural analysis on larval zebrafish have shown that synaptic ribbons in photoreceptor terminals undergo structural changes over the course of the day and that this process is circadian driven. The implications of this circadian driven process on visual function are not well understood. Further analysis of synaptic ribbons may help identify its role in normal vision and in disease states.

描述(申请人提供)：对几个物种的研究表明，许多视觉现象受昼夜节律机制的调节。例如，斑马鱼幼体光感受器末端的突触带每天都会发生戏剧性的变化。这些丝带在白天非常突出，但在晚上几乎完全不存在。这种昼夜节律驱动的过程对视觉功能的影响还没有被很好地理解。拟议的实验旨在研究斑马鱼幼体眼睛中突触带的可塑性与视觉反应之间的关系。初步研究表明，5日龄的幼鱼白天视网膜电信号(ERGs)正常，但晚上对光照没有反应。视动力反应(OKR)和视觉-运动反应(VMR)两种行为测试表明，不仅斑马鱼幼体的视觉反应在白天和晚上的波动很大，而且这种视觉可能在晚上完全丧失。在具体目标1中，我将确定斑马鱼幼体ERG和视觉行为敏感度的变化是如何随着一天中的时间和光照的变化而变化的。单单位和ERG记录将被用来确定视网膜内和外视网膜细胞功能特性的变化。OKR和VMR测试将被用来确定一天中的时间和光照如何影响斑马鱼的视觉反应和行为。在具体目标2中，我将表征和量化在生理条件下以及在各种明暗条件下视网膜带状结构的变化。突触带的结构变化将通过电子显微镜或免疫组织化学研究，使用突触带蛋白抗体。与公共健康相关的斑马鱼已经成为研究视觉系统发育和分化过程的一个强大的模型系统。斑马鱼幼体的超微结构分析表明，光感受器终末的突触带在一天中经历了结构变化，这一过程是由昼夜节律驱动的。这种昼夜节律驱动的过程对视觉功能的影响还没有被很好地理解。对突触带的进一步分析可能有助于确定它在正常视力和疾病状态中的作用。