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: 7341614
• 负责人: William Rowland Taylor
• 金额: $ 28.49万
• 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/7341614
• 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

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 resultswill have particular relevance to diseases that cause night blindness.

对于捕食者和猎物以及许多哺乳动物来说，夜间视力具有相当大的进化优势， 包括人类在内，都具有出色的夜视能力。人类可以感知微弱的闪光，产生单一的 大约百分之一的棒中的光子被吸收，这表明单光子产生的信号 通过视网膜可靠地传输到大脑。我们详细了解了杆如何 光感受器将单个光子编码为电信号，但对于这些微小的光感受器如何编码相对较少 信号通过视网膜传输。本研究的总体目标是获得定量的 了解通过视网膜的单光子突触传递。我们将使用鼠标作为模型 系统，因为它们具有发达的夜视能力，并为 哺乳动物的视杆视觉。单光子信号的记录将从链中的每个神经元进行。 连接杆和神经节细胞的神经元。响应调光而生成的电压和电流信号 将分析闪光。具体目标包括 1) 确定杆处增益控制的机制 突触，2) 确定控制杆中收敛噪声的非线性的性质 所有无长突 细胞，3）解析神经节细胞中的单光子信号。我们对正常视网膜的理解取得进展 功能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 与引起夜盲症的疾病特别相关。