Researchers at the U.K.’s University of Edinburgh have discovered a new link between the eye and the human body clock.
This takes the form of a group of newfound cells in the retina which send information about light changes to the suprachiasmatic nucleus, the part of the brain responsible for circadian rhythms.
While links between the eyes and our natural body clocks have been known for a long time, the exact details of this relationship are unknown. The body’s biological clock is synchronized to changes in light and dark and plays an important role in maintaining everything from brain activity and regulation of body temperature to protecting against depression and gastrointestinal problems.
In a study by the researchers, lab rats were examined after the selective activation or destruction of these cells in the retina, which contain vasopressin, the neurohypophysial hormone that expresses changes after long haul travel or a person switching between day and night shifts. The results — which are described in The Journal of Physiology — showed the vasopressin-expressing cells in the retina play an active role in controlling circadian rhythms.
The scientists working on the project demonstrated that a bright flash of light seen by the rats caused them to release vasopressin and also activated neurons in the brain’s suprachiasmatic nucleus. However, when a vasopressin-blocking compound was injected into brain cells, the rats responded less significantly to light.
So does this lay the groundwork for the possibility that it might one day be possible to overcome jet lag by administering some eye drops? That is one of the goals of the project, but don’t expect it anytime soon.
“Nobody’s started to do anything like that yet,” Mike Ludwig, professor of neurophysiology at the University of Edinburgh, told Digital Trends. “It’s a way that this could go, but we’re not there yet. There’s a lot of work that still needs to be done on the basic research part. You won’t be able to go to the chemist in the next two or three weeks, and buy eye drops when you have a long flight. We’re talking about years, but the opportunity is possibly there.”