动物实验 z-bo 2020-08-31 419

　　Recently, the Samer Hattar research group of Johns Hopkins University in the United States has made a breakthrough in the study of the mechanism of visual contrast, in which Optomelanin and α retinal ganglion cells play an important role. Different subtypes of retinal ganglion cells (RGC) mediate visual and non-imaging functions, such as physiological phototaxis.

　　Samer Hattar's team found a difference when studying light-sensitive retinal ganglion cells (ipRGC) endogenously expressed by injured optomelanin. However, when studying the conventional RGC-ONalphaRGC, it is sensitive to endogenous light in mammals. In addition to the classic fast response of the rod/cone signal path to contrast, the visual melanin expression also enables ONalphaRGC to receive signals preferentially, rather than exposure to intensity and long-term bright environments. Consistent with the high contrast sensitivity of ONalphaRGC, mice lacking visual melanin or ONalphaRGC have poor contrast sensitivity. This study pointed out that Optomelanin and ipRGC have surprising functions in vision.