PORTLAND, Ore. - A drug used to treat high blood pressure and enlargement of the prostate may protect the brain from damage caused by post-traumatic stress disorder, Alzheimer's disease, depression and schizophrenia.
Prazosin, also prescribed as an antipsychotic medication, appears to block the increase of steroid hormones known as glucocorticoids, Oregon Health & Science University and Portland Veterans Affairs Medical Center researchers have found. Elevated levels of glucocorticoids are associated with atrophy in nerve branches where impulses are transmitted, and even nerve cell death, in the hippocampus.
The hippocampus is the elongated ridge located in the cerebral cortex of the brain where emotions and memory are processed.
"It's known, from human studies, that corticosteroids are not good for you cognitively," said study co-author S. Paul Berger, M.D., assistant professor of psychiatry and behavioral neuroscience, OHSU School of Medicine and the PVAMC. "We think prazosin protects the brain from being damaged by excessive levels of corticosteroid stress hormones."
The study, titled "Prazosin attenuates dexamethasone-induced HSP70 expression in the cortex," is being presented during a poster session today at Neuroscience 2007, the annual Society for Neuroscience conference in San Diego.
Scientists believe stress activates a neurochemical response in the brain that triggers the release of glucocorticoids in the brain, and that high levels of glucocorticoids in blood serum are associated with such psychiatric conditions as schizophrenia, depression, PTSD and Alzheimer's disease. This mechanism has been linked to decreases in cognitive performance in older people who are not suffering from clinical dementia.
"Our hypothesis is that just being afraid of being blown up all the time means you have high levels of steroids all the time," Berger said, referring to PTSD among military personnel.
|Contact: Jonathan Modie|
Oregon Health & Science University