ANATOMY AND PHYSIOLOGY OF VISION

视觉的解剖学和生理学

• 批准号: 3260036
• 负责人: JOEL E BROWN
• 金额: $ 21.29万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-10-01 至 1994-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3260036
• 关键词: 3'5' cyclic nucleotide phosphodiesterase; Anura; bioassay; cyclic GMP; electrophysiology; fresh water environment; guanylate cyclase; high performance liquid chromatography; horseshoe crabs; ion exchange chromatography; light adaptations; membrane channels; neuroanatomy; neurophysiology; phosphatidylinositols; photochemistry; radioimmunoassay; rod cell; saltwater environment; vision; visual photoreceptor; visual phototransduction

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 in conductance of the plasma membrane are not entirely understood. Moreover, the sequence of events that modulate the transduction of excitation to produce "adaptation" are also incompletely understood. Our specific aims include the design and performance of experiments to test current hypotheses for intracellular signalling of excitation and adaptation in both vertebrate and invertebrate photoreceptors. We propose to examine the participation of phosphoinositide metabolism in the modulation of excitatory transduction (that is mediated by changes of cGMP concentration within vertebrate rods). These assays will include determination of time course of changes in inositol polyphosphates on a rapid time scale using either rapid-freezing or microwave heating techniques, or both. We propose to investigate the candidacy of cGMP as the excitatory messenger within Limulus ventral photoreceptors by both biochemical and electrophysiological experiments. We will assay for light activation of guanylate cyclase, cGMP-phosphodiesterase, and changes in cGMP content. We will also assay the effects of pharmacological agents on these enzymes, on cGMP content and on the light responses recorded electrophysiologically. We also propose to produce "concentration jumps" of intracellular cGMP in Limulus photoreceptors by the use of "caged cGMP".

我们的长期目标是物理化学和分子 理解光转导过程 感光细胞。 事件顺序的细节 通过连接光子吸收光子的刺激 对质膜电导变化变化的照相是 不完全理解。 而且，事件的顺序 调节激发的转导以产生“适应”为 也不完全理解。 我们的具体目的包括实验的设计和性能 测试当前假设的细胞内信号传导 脊椎动物和无脊椎动物的激发和适应 感受器。 我们建议检查 磷酸肌醇代谢在调节兴奋性的调节中 转导（通过CGMP浓度的变化介导 在脊椎动物杆中）。 这些测定将包括决策 快速肌醇多磷酸盐变化的时间过程 使用快速冻结或微波加热的时间尺度 技术，或两者兼而有之。 我们建议调查 CGMP作为利利卢斯腹侧的兴奋性使者 受到生化和电生理学的感光体 实验。 我们将测定鸟烯基的光激活 Cyclase，CGMP-磷酸二酯酶以及CGMP含量的变化。 我们 还将分析药理学剂对这些的影响 酶，CGMP含量以及记录的光反应 电生理学。 我们还建议产生“浓度 利用利用物中细胞内CGMP的跳跃” 的“笼子CGMP”。