In the future, a drug could allow you to move from Australia to U.S. time jet lag free.
Researchers pinpointed the gene responsible for regulating the internal clock through changes in light. They made the discovery by studying mice, a Wellcome Trust press release reported.
"We've identified a system that actively prevents the body clock from re-adjusting. If you think about, it makes sense to have a buffering mechanism in place to provide some stability to the clock. The clock needs to be sure that it is getting a reliable signal, and if the signal occurs at the same time over several days it probably has biological relevance. But it is this same buffering mechanism that slows down our ability to adjust to a new time zone and causes jet lag," Dr. Stuart Peirson, a co-leader of the Oxford University study, said.
Almost all living things (including plants) have an "internal circadian body clock" that keeps them regulated to the 24-hour solar cycle. This clock could take a full day for every one hour of adjustment, so traveling to an area with an eight-hour time difference might require an eight0day adjustment period.
For mammals, the circadian clock is controlled by an area of the brain called the suprachiasmatic nuclei (SCN).
"It receives information from a specialized system in the eyes, separate from the mechanisms we use to 'see', which senses the time of day by detecting environmental light, synchronizing the clock to local time," the press release stated.
The research team observed how genes in the SCN reacted to pulses of light during the dark hours. They found that about 100 genes "switched on" when presented with a when presented with the stimulus. This response is a step in the retuning of the circadian clock.
One molecule, called SIK1, blocked the response. The researchers found that it "[acted] as a brake to limit the effects of light on the clock." If S1K1 was blocked the mice adjusted to changes in light much faster.
Frequent disturbances in the circadian clock can lead to "cancer, diabetes, and heart disease, as well as weakened immunity to infections and impaired cognition. More recently, researchers are uncovering that circadian disturbances are a common feature of several mental illnesses, including schizophrenia and bipolar disorder."
