( the neurotransmitter GABA (gamma-aminob...)New understanding of jet lag

Block likens GABA to a weak rubber band linking pendulums swinging at different rates. If the "rubber band" could be made stronger, such as using a drug to enhance GABA, the ventral and dorsal parts of the central timekeeper could more quickly move back into harmony. The symptoms of jet lag would then be reduced or eliminated.

"The key here is, we now know what the 'rubber band' is: the neurotransmitter GABA that ultimately brings the clock back into synch," Block said. "This could lead to future therapies for jet lag. This is the first time that we have a mechanistic understanding of the systematic coupling of the different parts of the clock. We are now on our way to suggesting strategies for shifting the clock more quickly in response to unnatural light cycle changes."

Block said that future therapies, using this new knowledge, might also benefit shift workers and older people who suffer from sleep disorders.

In nature, day and night cycles shift slowly as the seasons change. The body is able to adjust to the slow changes and is in fact adapted to these seasonal cycles. But transmeridian flight is an unnatural manipulation of the light cycles, forcing the body to try to rapidly adjust to abrupt light cycle shifts. This sudden disruption in the normal pattern can compromise the normal function of organs. The result often is sleeplessness or sleepiness, reduced alertness, indigestion, fatigue and possibly ulcers.

"This new finding adds support to the emerging view that the central timekeeper, the SCN, is more complex than previously thought, and in fact adjusts to light cycle shifts at a different rate within its own structure," Block said. "Most importantly, the new research identifies t
'"/>

Source:University of Virginia