July 16, 2003
New type of cone cell identified
OSN 2003
Researchers at the University of Lyon believe they have found a new type of cone photoreceptor in the human retina containing the photopigment melanopsin, which may play a role in regulating circadian rhythms and other nonvisual but light-dependent mechanisms.The melanopsin was detected by performing anti-melanopsin immunohistochemistry on free-floating sections of retina obtained from human cadaver eyes. Previous studies have shown that melanopsin is expressed in a subpopulation of human retinal ganglion cells that are intrinsically photosensitive.Melanopsin expressing ganglion cells are considered to play a role in a broad range of nonvisual irradiance-detection processes due to their intrinsic photosensitivity and projections to structures mediating circadian rhythms, pupillary reflex and seasonal rhythms. A similar role can be hypothesized for melanopsin in the human retina.
Posted by kjalali at July 16, 2003 06:45 AM