GSU project to study how the body's internal clock is reset

Georgia State University's H. Elliott Albers, the Regents' Professor of Neuroscience and director of the Center for Behavioral Neuroscience, has received a four-year, $1.3 million grant from the National Institutes of Health to study how the body's internal clock is "reset," a key to understanding more about sleep and other disorders affecting human health.

Albers' studies how the internal, or circadian, clock is synchronized to the day-night cycle so that it times many of the body's processes in a roughly 24-hour pattern. The clock is composed of about 10,000 neurons above the roof of the mouth.

The project funded by the grant will focus on the chemical process in which the clock is reset by light. Albers and his lab found they could mimic the effects of light seen by the eye on the clock by injecting a neurotransmitter, a chemical called glutamate, into the clock itself.

"Glutamate communicates light information from the eye into the clock," Albers said.

He said there are two parts of the internal clock, a non-clock element that receives information from other parts of the body and the clock itself.

"What we're trying to understand now is how the information from the non-clock part talks to the clock part and actually resets it," he said. "We're proposing that it takes several hours of neurotransmitter activity to actually reset the clock in response to even very brief exposure to light."

The neurotransmitter involved in this process, called GABA, is the primary inhibitory neurotransmitter in the brain, and understanding how it works could be a key to understanding basic communication among cells in brain.

GABA-active drugs are some of the most commonly prescribed drugs in the world for numerous issues, including sleep disorders and depression.

"We're potentially looking at different kinds of receptors that haven't really been seen before for GABA," Albers said. "This really could have an impact in understanding how GABA acts in the brain, which relates to lots of kinds of disorders."

Health problems related to shift work and jet lag are well known, but scientists are seeing more impacts of disrupting the internal clock on other diseases such as cancer.