McLEAN IN THE NEWS
Study Identifies Critical Brain Areas Involved in Stress and Anxiety
May 31st, 2006Researchers have discovered what they believe to be a principal brain mechanism leading to a heightened state of anxiety and possibly, depression. The finding, published in the April 5 issue (abstract) of the Journal of Neuroscience, has the potential to help the more than 45 million of American adults who suffer from anxiety and depression each year, says lead author Edward Meloni, PhD. Meloni, of the MRC's Behavioral Genetics Laboratory, and colleagues reported on their ability to neutralize the effects of anxiety by preventing a chemical reaction in the brain using an experimental drug called a D1 antagonist, which blocks the neurotransmitter dopamine at a specific receptor subtype known as D1. This is the first time that researchers have been able to identify dopamine as a likely culprit in amplifying the response to stress, an advance that could have important implications for those suffering from anxiety disorders and certain types of depression. The newly identified dopamine pathway also involves a brain chemical called corticotropin-releasing factor (CRF). CRF has been found in high amounts in people with some types of anxiety and depression, and a rise in CRF levels has been shown previously to put rats into a heightened state of anxiety. These results are opening new avenues for future research, including testing with D1 antagonists in people with anxiety and/or depression. Meloni also hopes to use animal models to learn whether this brain circuit is more susceptible to trauma and stressors in early development that could predispose an individual to anxiety disorders and depression in adulthood. His team is continuing this research to better understand the connection between dopamine and CRF, with the hopes of eventually developing early interventions and treatment for their debilitating psychiatric disorders.