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(申请人提供)：夜间视力对捕食者和猎物都有相当大的进化优势，许多哺乳动物，包括人类，都有很好的夜视能力。人类可以感知到微弱的闪光，这种闪光产生的单光子吸收约为100根棒中的1根，这表明由单光子产生的信号可以可靠地通过视网膜传输到大脑。我们对杆状感光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知之甚少。这项研究的总体目标是对单光子突触通过视网膜的传递有一个定量的了解。我们将使用小鼠作为模型系统，因为它们有很好的夜视能力，是一个很好的哺乳动物杆状视觉的模型系统。单光子信号的记录将来自连接杆状细胞和神经节细胞的神经元链中的每个神经元。本课程将分析因微弱闪光而产生的电压和电流信号。具体目标包括1)确定视杆突触的增益控制机制，2)确定控制视杆所有无长突细胞中会聚噪声的非线性的性质，3)分辨神经节细胞中的单光子信号。我们对正常视网膜功能的了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的疾病特别相关。