Scientists Discover How to Reset the Body’s Circadian Rhythm

Lisa Franchi April 29, 2015

A group of researchers at McGill and Concordia universities in Montreal has identified the mechanism in which an individual’s body clock can be reset. Their findings, published in Nature Neuroscience, could pave way to treat a range of disorders, from sleep disturbances to cognitive, behavioural and metabolic abnormalities, as well as neuropsychiatric conditions such as depression and autism.

The process is called phosphorylation and is triggered by light. It stimulates the synthesis of specific proteins called Period proteins which play a major role in resetting the body clock, thereby synchronising the internal clock’s rhythm with daily environmental cycles.

"This study is the first to reveal a mechanism that explains how light regulates protein synthesis in the brain, and how this affects the function of the circadian clock," according to Nahum Sonenberg, senior author of the study and a professor in McGill’s Department of Biochemistry.

In order to examine the brain clock’s mechanism, the researchers mutated a protein known as eIF4E to prevent the process of phosphorylation in the brains of lab mice. This allows them to have a clearer idea of what would happen if the function of this protein were blocked in humans.

Results showed that those with mutated gene responded less efficiently to the resetting effect of the light. The mutants were unable to synchronise their body clocks to a series of challenging light/dark cycles. For example: 10.5 hours of light followed by 10.5 hours of dark, instead of the 12-hour cycles to which they were usually exposed.

The researchers note that the study findings could open a path to target the problem at its very source. "Disruption of the circadian rhythm is sometimes unavoidable but it can lead to serious consequences. This research is really about the importance of the circadian rhythm to our general well-being. We’ve taken an important step towards being able to reset our internal clocks—and improve the health of thousands as a result." says Shimon Amir, co-author of the study and professor of Psychology at Concordia University.

Source of this article: Light-regulated translational control of circadian behavior by eIF4E phosphorylation