学术报告
题目：Melanopsin Signaling in Mammalian Iris and Retina—a Novel Light Detection Mechanism for Non-Image Vision
报告人：Tian Xue, Ph.D.
The Solomon H. Snyder Department of Neuroscience,
The Johns Hopkins University School of Medicine
时间：Tuesday 10:00 a.m., December 20
地点：生命科学学院411会议室
Sensing light signals provides us with visual perception (image vision) but also regulates many important physiological functions such as circadian-rhythm photoentrainment, pupillary light reflex, sleep, locomotion and secretion of melatonin – functions referred to collectively as non-image vision. It had been a century-old dogma that retinal rods and cones are the only mammalian photoreceptors for both forms of vision, until the discovery of a small group of intrinsically photosensitive retinal ganglion cells (ipRGCs) for non-image vision, which express melanopsin as their visual pigment. After the discoveries of melanopsin and ipRGCs, there were two major questions. One is how melanopsin signals in the ipRGCs. The other is whether there are additional intrinsically photosensitive cells other than rods, cones and ipRGCs in the mammalian eye. In this talk, I will discuss my most recent discovery of the key phototransduction components in ipRGCs. I will also discuss a surprising discovery that the iris can sense light by itself and trigger intrinsic pupil constriction in many mammals, which is mediated also by melanopsin expressed in the iris. Phototransductions in both ipRGCs and iris use similar upstream components, but nonetheless diverge in the two locations. In the end, two branches of my future research will also be introduced, including both signal transduction in non-image vision and stem-cell based photoreceptors regeneration for image vision.
欢迎各位老师和同学积极参加！