Intrinsic photosensitivity of retinal ganglion cells

描述(申请人提供)：在经典视觉中，视网膜神经节细胞传递由视杆和视锥产生的光信息。一种独特的神经节细胞群的发现改变了这种模式：这些中继器本身就是光感受器，并告知不同的、非成像的视觉过程，如昼夜节律光携带、瞳孔光反射和运动的急性抑制。人们对这些神经元的光敏感机制知之甚少。这项拟议的研究将首先确定它们的动作电位是如何由光刺激的内在信号和突触信号驱动的。本征光电流将被表征，包括它对光和电压的敏感性，它的动力学，它的离子选择性，以及它的第二信使的电势门控。这些信息将有助于指导对光转导级联的分子遗传学探索。光通常被认为是从视觉感知的角度来看的，但它对生理学的广泛重要性在季节性情感障碍和时差等疾病中显而易见，在这些疾病中，光起着主要作用。了解感光神经节细胞将有助于理解基础的、光依赖的生理学及其在疾病中的障碍。

DESCRIPTION (provided by applicant): In classical vision, retinal ganglion cells relay light information generated by rods and cones. The discovery of a unique ganglion cell population has changed this model: these relays are themselves photoreceptors, and inform diverse, non-image-forming visual processes such as circadian photoentrainment, the pupillary light reflex, and the acute suppression of movement. Little is known about the mechanism of light sensitivity in these neurons. The proposed research will begin by determining how their action potentials are driven by light-stimulated intrinsic and synaptic signals. The intrinsic photocurrent will then be characterized, including its sensitivity to light and voltage, its kinetics, its ionic selectivity, and its potential gating by second messengers. The information will help guide a molecular genetic exploration of the phototransduction cascade. Light is often considered in terms of visual perception, but its widespread importance to physiology is evident in ailments such as seasonal affective disorder and jet lag, where it plays the major role. Understanding the photosensitive ganglion cells will help in understanding basic, light-dependent physiology and its disturbance in illness.