Properties and Mechanisms of Melanopsin Photoreception

The long-term goal of this project is to understand the generation and transmission of signals by cells in the mammalian, "non-image" visual pathway. Non-image vision is important to embryonic and early postnatal development; it supports the proper formation of retinal neurons and vasculature, as well as of the connections between retina and brain. An integral part of this pathway is a population of intrinsically photosensitive retinal ganglion cells (ipRGCs), photoreceptors that capture light with a receptor molecule called melanopsin. The immediate aims of this project are to investigate the mechanisms by which ipRGCs sense light with the high degree of temporal and spatial integration that is characteristic of non-image vision. We hypothesize that temporal and spatial integration allows ipRGCs to sense light even in dim environments such as the womb. We seek to define the mechanisms of integration in ipRGCs of both adult and developing organisms, taking a primarily electrophysiological approach.