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‘Molecular basis’ for jet lag found

'Molecular basis' for jet lag foundResearchers at Oxford University say they have found the “molecular brakes” that prevent light resetting the body clock when we fly — causing jet lag. Experiments, reported in the journal Cell, showed “uncoupling” these brakes in mice allowed them to rapidly adapt. Researchers hope the discovery will help find new drugs for jet lag and mental health treatments.
The body clock keeps us in tune with the pattern of day and night. It means we sleep at night, but also affects hunger, mood and blood pressure. Light acts like a reset button to keep the clock to time, but when we fly around the world it takes time for our body clocks to adjust. The resulting fatigue, which can last for days, is known as jet lag
Master clock
The research team was trying to figure out why people do not instantly adapt. They looked in mice as all mammals have the same core body clock mechanisms.
They focused on the “master clock” in a part of the brain, which keeps the rest of the body in sync, called the suprachiasmatic nuclei. They were looking for sections of DNA that changed their activity levels in response to light.
They found a huge numbers of genes were activated, but then a protein called SIK1 went round turning them all off again. It was acting as a brake by limiting the effect of light. Experiments to reduce the function of SIK1 meant the mice could rapidly adjust their body clock when it was shifted six hours — the equivalent of a flight from the UK to India.
Reset
Prof Russell Foster said, “We reduced levels by 50-60%, which is big enough to get a very, very big effect. What we saw was the mice would actually advance their clock six hours within a day [rather than taking six days for untreated mice].
He said some mental health disorders including schizophrenia were linked to an out-of-tune body clock, so these findings may open up new areas for research.

Source - The Daily Star