Light Adaptation in Cone Photoreceptors

视锥细胞感光器的光适应

• 批准号: 7007325
• 负责人: FREDERICK SAMUEL SOO
• 金额: $ 4.99万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-12-01 至 2007-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7007325
• 关键词: Urodela; cone cell; cyclic GMP; enzyme activity; guanylate cyclase; light adaptations; light intensity; phosphodiesterases; photostimulus; postdoctoral investigator; rod cell; visible light; vision; vision tests; visual photosensitivity; visual phototransduction; visual stimulus

DESCRIPTION (provided by applicant): Cones mediate everyday vision, and how cones adapt to bright illumination is an intrinsic part of their function. Despite their importance to vision, little is known about how cones adapt to light. The research proposed here aims to elucidate the molecular mechanisms of light adaptation in cones, and dissect how these mechanisms impact the function and performance of the cone in bright light. The first specific aim determines how cones respond to prolonged background light, focusing on slow changes in circulating current in response to steady illumination. The second specific aim determines how the gain and speed of the photo transduction cascade changes under background light by studying the kinetics of the dim flash response. The third specific aim measures the sensitivity and contribution of specific components of the photo transduction cascade to adaptation. These experiments test how specific mechanisms regulate the gain and speed of the photo transduction cascade during adaptation. A suction electrode technique is used throughout, which allows recording from individual, intact photoreceptors.

描述（由申请人提供）：视锥细胞介导日常视觉，视锥细胞如何适应明亮的照明是其功能的固有部分。尽管视锥细胞对视觉很重要，但人们对视锥细胞如何适应光线知之甚少。本研究旨在阐明视锥细胞光适应的分子机制，并剖析这些机制如何影响视锥细胞在强光下的功能和表现。第一个特定的目标是确定视锥细胞如何对长时间的背景光做出反应，重点是响应稳定照明的循环电流的缓慢变化。第二个具体目标是通过研究微弱闪光响应的动力学来确定光转导级联的增益和速度在背景光下如何变化。第三个具体目标是衡量光传导级联反应中特定成分对适应的敏感性和贡献。这些实验测试了在适应过程中特定机制如何调节光转导级联的增益和速度。整个过程中使用了一种抽吸电极技术，它允许从单个完整的光感受器进行记录。