The team, from Oxford University, looked at the genes that
govern the way our body adjusts to changing patterns of light and darkness. They
found 100 genes that help to reset the body clock, and also one protein, SIK1,
that slows down this response, acting as a 'molecular brake'.
When the gene that expresses the SIK1 protein was blocked in
mice, the researchers found that the mice were able to adjust to shifting light
patterns much faster.
'We've identified a system that actively prevents the body
clock from re-adjusting', said Dr Stuart Peirson, who led the team. 'If you
think about it, 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'.
The researchers investigated a part of the brain known as
the suprachiasmatic nuclei that governs the body's 24-hour cycle. This
uses information from the eyes about environmental light that is used to
synchronise the body clock.
It is hoped that by targeting the SIK1 molecule, scientists will
be able to create a drug that can alleviate the symptoms of jet lag.
'We're still several years away from a cure for jet-lag, but
understanding the mechanisms that generate and regulate our circadian clock
gives us targets to develop drugs to help bring our bodies in tune with the
solar cycle', said Professor Russell Foster, from the Oxford University Sleep and Circadian
Mental health disorders such as schizophrenia have recently
been linked with an
out-of-sync body clock. Professor Foster added: 'Such drugs could potentially
have broader therapeutic value for people with mental health issues'.