Baylor Researcher Starts New Study On PTSD

Aug. 2, 2006
News Photo 3666Dr. Brad Keele

by Frank Raczkiewicz

As the conflict continues in Iraq, Afghanistan and other foreign places, the prevalence of more troops coming home with post traumatic stress disorder (PTSD) has become a growing concern among doctors, politicians and researchers. An estimated eight percent of the general adult population has PTSD, but the risk of getting the disorder is greatly increased to more than 30 percent in military veterans who experience combat.

Currently, there is a limited number of effective prescription drugs available to patients to help treat PTSD. But a new research project just underway at Baylor University aims to provide new experimental data that could be used as the scientific basis for more effective drug treatments.

"PTSD is one of the most difficult disorders to treat," said Dr. Brad Keele, the project's principal researcher and an associate professor of psychology and neuroscience at Baylor. "It is a debilitating disorder and can lead to a wide range of other problems - from mood disorders to alcoholism."

Keele said neuroimaging studies in humans who have PTSD show over-activity in a specific part of the brain called the amygdala. The amygdala is a limbic structure that is crucial in controlling fear and anxiety. Keele and his research team will study the specific serotonin levels in the amygdala. Serotonin has an inhibitory role and acts like the "brakes" on amygdala excitability. Keele said evidence shows that PTSD suffers have significantly lower serotonin levels in the amygdala. Baylor's project will test that theory and will study the cellular and molecular mechanisms that are contributing to the PTSD-mind state.

"In PTSD patients, the theory is if the circuits in the amygdala get super-sensitized, things don't work right and that might be part of the hyperactive startle-reflex problem," Keele said. "Our work will look at things like different neurotransmitters, ion channels and protein expressions in the amygdala and how all that relates to fear and anxiety."

Using rodent test subjects, researchers will investigate the fear-potentiated startle, which is critically dependent on the amygdala. Keele said they will test whether the neuronal hyperexcitability in the amygdala is associated with PTSD-like increased startle in rats.

"The results of these experiments will give us important information about the functional role of excitability in the amygdala, which could ultimately lead to specifically targeted therapeutic drugs for PTSD treatment," Keele said.

For more information, contact Brad Keele at (254) 710-2961.

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