An international team of scientists has unearthed a molecular reset button for our internal body clock. The findings show a potential target to treat several disorders including sleep disturbances, behavioral, cognitive and metabolic abnormalities, commonly linked to jet lag, shift work and exposure to light at night. It may also help doctors deal with neuropsychiatric conditions like depression and autism.
Conducted by researchers at McGill and Concordia universities in Montreal the study says that the body’s clock is reset when a phosphate combines with a key protein in the brain. Called phosphorylation, this process, is triggered by light. Specific proteins called Period proteins play a crucial role in synchronizing the clock’s rhythm with daily environmental cycles. Light stimulates the synthesis of these proteins.
This is the first study to shed light on how light regulates protein synthesis in the brain, and how this affects the function of the circadian clock.
For studying the mechanism of the brain’s clock, the researchers mutated eIF4E, a protein in the brain of a lab mouse to ensure that it could not be phosphorylated. Because all mammals have similar brain clocks, the experiments give an idea of the impact of blocking the function of this protein in humans.
They recording and analyzed the running activity of the animals kept in cages equipped with running wheels. The aim was to study the rhythms of the circadian clock in the mutant mice. The upshot: the normal mice responded far more efficiently than their mutant brethren to the resetting effect of light. The latter failed to synchronize their body clocks to a number of challenging light/dark cycles.
“While it is difficult to say when these findings could translate into clinical use, the study does open a new window to control the functions of the circadian clock,” says Ruifeng Cao, a postdoctoral fellow in Dr Sonenberg’s research group and lead author of the study.
Added co-author Shimon Amir: “The research may open a path to go after the very source of the problem. Sometimes disruption of the circadian rhythm is inescapable but can cause grim consequences. The study is essentially focused on the significance of the circadian rhythm to general well-being. It is an important step in the direction of being able to reset our internal clocks – and, as a result, improve the health of thousands.”