A study from scientists at Cincinnati Children’s and the University of Washington School of Medicine in published Oct. 10 in Current Biology now finds that a type of opsin known as neuropsin is expressed in the hair follicles of mice and synchronize the skin’s circadian clock to the light-dark cycle, independent of the eyes or brain.
“Although our research is still underway, we hypothesize that specific colors of light at certain times of day will influence how the skin heals,” said co-lead investigator Richard Lang, PhD, Division of Pediatric Ophthalmology at Cincinnati Children’s and Director of our Visual Systems Group. “The potential for using circadian rhythms to enhance medical practice is a growing field of study. Recent work has shown that the timing of medication administration at specific hours of the day or night can have a major influence on drug effectiveness. It is likely that this same observation applies to skin mediations.”
The study is the first functional demonstration of opsin photoreceptors outside the eye directly controlling circadian rhythms in a mammal, according to co-lead author Ethan Buhr, research assistant professor of ophthalmology at the University of Washington School of Medicine.
Buhr said it was assumed that, when mammals evolved, the brain took over informing all organs of the body if it was day or night. But, he said, this study found that the skin actually expresses its own photoreceptors using a previously mysterious member of the opsin gene family, neuroposin.
This means that skin can sense whether it is day or night even when it’s cultured by itself in a dish.