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: 7167419
• 负责人: William Rowland Taylor
• 金额: $ 29.02万
• 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/7167419
• 关键词: Action Potentials; Amacrine Cells; Biological Models; Brain; Calcium; Cells; Chromosome Pairing; Class; Computer Simulation; Condition; Detection; Discrimination; Disease; Event; Feedback; Functional disorder; Goals; Human; Light; Mammals; Measures; Mediating; Morphology; Mus; Nature; Neurons; Night Blindness; Noise; Pathway interactions; Photons; Physiological; Principal Investigator; Property; Research; Retina; Retinal; Retinal Cone; Retinal Diseases; Retinal Ganglion Cells; Rhodopsin; Signal Transduction; Stimulus; Synapses; Synaptic Transmission; System; Testing; Vision; Visual system structure; absorption; ganglion cell; improved; multi-photon; neural circuit; postsynaptic; presynaptic; relating to nervous system; research study; response; retinal rods; transmission process; visual threshold; voltage; voltage gated channel

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）：夜间视力对于捕食者和猎物来说都具有相当大的进化优势，并且包括人类在内的许多哺乳动物都具有出色的夜视能力。人类可以感知到约百分之一的视杆细胞产生单光子吸收的微弱闪光，这表明单光子产生的信号可以通过视网膜可靠地传输到大脑。我们对视杆光感受器如何将单个光子编码为电信号有详细的了解，但对这些微小信号如何通过视网膜传输的了解相对较少。这项研究的总体目标是定量了解通过视网膜的单光子突触传输。我们将使用小鼠作为模型系统，因为它们具有发达的夜视能力，并且为哺乳动物的视杆视觉提供了一个出色的模型系统。连接杆和神经节细胞的神经元链中的每个神经元都会记录单光子信号。将分析响应暗光闪烁而生成的电压和电流信号。具体目标包括 1) 确定杆突触的增益控制机制，2) 确定控制杆所有无长突细胞中会聚噪声的非线性性质，3) 解析神经节细胞中的单光子信号。我们对正常视网膜功能理解的进步将提高我们对视网膜疾病引起的功能障碍的理解。我们的结果将与导致夜盲症的疾病特别相关。