A small molecule called VIP, known to synchronize time-keeping neurons in the brain’s biological clock, has the startling effect of desynchronizing them at higher dosages, says a research team at Washington University in St. Louis. Neurons knocked for a loop by a burst of VIP are better able to re-synchronize to abrupt shifts in the light-dark cycle like those that make jet lag or shift work so miserable.
In the June 5 issue of Neuron, WUSTL biologist Erik Herzog and his colleagues report the discovery of a crucial part of the biological clock: the wiring that sets its accuracy to within a few minutes out of the 1440 minutes per day. This wiring uses the neurotransmitter, GABA, to connect the individual cells of the biological clock in a fast network that changes strength with time of day.
Researchers at Washington University in St. Louis have shown that individual cells isolated from the biological clock can keep daily time all by themselves. However, by themselves, they are unreliable. The neurons get out of synch and capriciously quit or start oscillating again.