Retinal clock regulates vision

The mammalian retina contains its own circadian clock that processes visual information without input from the master circadian clock in the brain, according to a report in this week's Cell. This clock may allow the retina to adjust its sensitivity to light by anticipating daily cycles of light and darkness. The mammalian master circadian clock lies in the suprachiasmatic nucleus (SCN) of the brain, but other tissues also show circadian oscillations in gene expression. "This is really important, because this is one of the few papers that actually shows a physiological role for the circadian clock outside of the suprachiasmatic nucleus," said Gianluca Tosini of Morehouse School of Medicine in Atlanta, Ga., who was not involved in the work. Previous work has shown that there are circadian rhythms in visual sensitivity and retinal electrical responses, said Michael Iuvone of Emory University in Atlanta, Ga., who was not involved in...