Biophysical limitations to signal transmission in the mammalian retina

哺乳动物视网膜信号传输的生物物理限制

• 批准号: 7019323
• 负责人: William Rowland Taylor
• 金额: $ 29.54万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-01-15 至 2009-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7019323
• 关键词: action potentials; amacrine cells; dark adaptation; laboratory mouse; neural information processing; neural transmission; retina; retinal bipolar neuron; retinal ganglion; rod cell; visible light; visual photosensitivity; visual phototransduction; visual stimulus

DESCRIPTION (provided by applicant): Seeing at night has considerable evolutionary advantages both for predators and prey, and many mammals, including humans, have excellent night vision. Humans can perceive dim light flashes that produce single photon absorption in about 1 in 100 rods, which indicates that signals generated by single photons are reliably transmitted through the retina to the brain. We have a detailed understanding about how the rod photoreceptors encode single photons as electrical signals, but relatively little is known about how these tiny signals are transmitted through the retina. The general goal of this research is to gain a quantitative understanding of single photon synaptic transmission through the retina. We will use the mouse as a model system, because they have a well-developed night vision, and make an excellent model system for mammalian rod vision. Recordings of single photon signals will be made from each neuron in the chain of neurons connecting the rods to the ganglion cells. Voltage and current signals generated in response to dim light flashes will be analyzed. Specific aims include 1) determining the mechanisms of gain control at the rod synapse, 2) determining the nature of the non-linearity that controls convergent noise in the rod All amacrine cells, 3) resolving the single photon signal in ganglion cells. Advances in our understanding of normal retinal function will improve our understanding of the dysfunctions that result from retinal disease. Our results will have particular relevance to diseases that cause night blindness.

描述（由申请人提供）：夜间观察对捕食者和猎物都具有相当大的进化优势，以及包括人类在内的许多哺乳动物都具有出色的夜视。人类可以感知昏暗的光闪烁，从而在100个棒中大约有1个吸收单个光子吸收，这表明由单个光子生成的信号可靠地通过视网膜传播到大脑。我们对杆光感受器如何将单个光子编码为电信号有详细的了解，但是对于如何通过视网膜传输这些微小信号的知识相对较少。这项研究的一般目标是对通过视网膜进行单个光子突触传递的定量了解。我们将使用鼠标作为模型系统，因为它们具有发达的夜视，并为哺乳动物杆视觉提供了出色的模型系统。单个光子信号的记录将由连接杆连接到神经节细胞的神经元链中的每个神经元进行。将分析响应昏暗的光闪光的电压和电流信号。具体目的包括1）确定杆突触处的增益控制机制，2）确定控制杆中所有无链氨酸细胞中收敛噪声的非线性性质，3）解决神经节细胞中的单个光子信号。我们对正常视网膜功能的理解的进步将改善我们对视网膜疾病引起的功能障碍的理解。我们的结果将与引起夜失明的疾病特别相关。