ANATOMY AND PHYSIOLOGY OF VISION

视觉的解剖学和生理学

基本信息

批准号：
3260032
负责人：
JOEL E BROWN
金额：
$ 14.87万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1983
资助国家：
美国
起止时间：
1983-07-01 至 1989-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/3260032
关键词：
Urodela bioenergetics calcium cyclic GMP dyes fresh water environment horseshoe crabs ionophores light adaptations membrane channels membrane permeability microspectrophotometry neuroanatomy neurophysiology photochemistry rod cell saltwater environment visual photoreceptor

项目摘要

Our long-term objective is a physical-chemical and molecular understanding of the processes of phototransduction in photoreceptor cells. The details of the sequence of events that mediates excitation by linking the absorption of photons by photopigments to changes of permeability of the plasma membrane are still poorly understood. Moreover, the sequence of events that modulate transduction processes to produce "adaptation" are also poorly understood. Our specific aims include the design and performance of experiments to test current hypothesis for intracellular signaling of excitation and adaptation in both vertebrate and invertebrate photoreceptors. We propose to compare the reversal voltages of membrane currents induced by injection of both Ca++ and cGMP into vertebrate rods with the reversal voltage of light-induced current, as measured in voltage-clamp. We also will examine the ability of Ca++ to control conductance channels in the plasma membrane of rod outer segments using the "patch-clamp" technique. We propose to re-examine the kinetics of the light-induced decrease of cGMP in rods by use of rapid microwave inactivation of rod enzymes. In addition, we propose to continue the examination of the kinetics and spatial distribution of light-induced changes of intracellular Ca++ in Limulus ventral photoreceptor cells using a rapid-scanning microphotometer. Also, we propose to investigate changes of voltage across intracellular membranes using voltage-sensitive dyes.

我们的长期目标是物理化学和分子理解光感受器细胞中光转传的过程。细节通过联系吸收光子，通过光成色对渗透率的变化质膜仍然知之甚少。而且，调节转导过程以产生“适应”的事件是也很少理解。我们的具体目的包括测试实验的设计和性能目前的假设用于激发和适应的细胞内信号在脊椎动物和无脊椎动物感光体中。我们建议比较两者都注射引起的膜电流的逆转电压 Ca ++和CGMP进入脊椎动物杆，并具有逆转电压光诱导的电流，如电压夹中测量。我们还将检查 CA ++控制质膜中电导通道的能力使用“斑块钳”技术的杆外段我们建议通过重新检查杆中光诱导的CGMP降低的动力学。使用杆酶快速的微波失活。另外，我们建议继续检查动力学和空间 Limulus中细胞内Ca ++的光引起的变化的分布腹侧光感受器细胞使用快速扫描的显微镜计。还，我们建议研究跨细胞内膜的电压变化使用对电压敏感的染料。