Eye cells that directly affect our body clock have been identified by scientists.
Cells in the retina communicate directly with areas of the brain to influence biological rhythms through a molecule called vasopressin, the study found.
The findings shed light on the mechanisms of the body clock and could help researchers understand how to overcome jet lag.
Daily biological cycles such as sleep, eating, and hormone patterns are known as circadian rhythms. Disruptions in these rhythms can lead to jet lag, and have been linked to cancers and mental illness.
Changes in light levels are detected by the eye and send signals to the brain to control circadian rhythms, but until now it was unclear how this happened.
The study – carried out with rats – shows for the first time that specific retinal cells control levels of vasopressin.
This opens up the possibility of new treatments to help restore disturbed circadian rhythms through the eye, say scientists.
The study was funded by the Biotechnology and Biological Sciences Research Council and the MRC and was published in The Journal of Physiology.
"Our exciting results show a potentially new pharmacological route to manipulate our internal biological clocks. Studies in the future that alter vasopressin signalling through the eye could lead to developing eye drops to get rid of jet lag, although we are still a long way off from this." Professor Mike Ludwig, Centre for Integrative Physiology
Source: The University of Edinburgh