Most mammalian tissues contain autonomous circadian clocks that are synchronized by the suprachiasmatic nuclei (SCN) in the brain. The SCN clock itself is entrained by external light cycles through retinal rods, cones, and melanopsin (OPN4)-expressing, intrinsically photosensitive retinal ganglion cells.  However, the retina does not follow this master clock, setting its own rhythms while sending the master clock the signals it needs to set the … Continue reading Researchers identify how the mammalian retina bypasses the body’s circadian clock.