December 5, 2008

Brain Area Blamed for Stress Disorders

Scientists have revealed an abnormality in the brain that may be at fault for stress-related psychiatric disorders. It lies in the part of the brain responsible for blocking out memories.

Using functional MRI (fMRI), scientists examined connections between the prefrontal cortex and hippocampus of participants who had suffered stressful traumatic events. The prefrontal cortex is the part of the brain that suppresses and retrieves memories processed by the hippocampus, another part of the brain. Researchers observed abnormal activation in the prefrontal cortex of participants with stress-related disorders.

Another discovery the researchers made suggests the part of the brain that suppresses memories -- the prefrontal cortex -- may function at a lower level in people with stress-related disorders than in healthy people. When participants with stress-related disorders were asked to suppress a memory of a specific word, their brains showed activation in the hippocampus that was greater than normal. Scientists say this could mean the prefrontal cortex is not doing its job properly.


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