Heavy drinking can affect your judgment, your family, your work life and your health.
According to a new study from the National Institute on Alcohol Abuse and Alcoholism and UNC’s Bowles Center for Alcohol Studies, chronic alcohol consumption also rewires the brain.
Heavy drinkers are more prone to car crashes and domestic violence, so scientists know there's a link between alcoholism and anxiety disorders such as post-traumatic stress disorder, which is especially common among returning war veterans.
Researchers set out to find the reason why by studying mice.
"You give them a cue, so a tone and then a shock, and what they do is they learn that a tone will predict shock," Tom Kash, UNC assistant professor of pharmacology, said of the mice in the study.
Kash says over the period of a month, one group of mice received doses of alcohol equal to double the legal driving limit in humans. A second group of mice received no alcohol.
Later, the mice would hear the tone but with no shock. Gradually, the non-alcohol mice stopped displaying fear after the tone – but the alcohol group continued to display the fear response.
"So this is a test that really specifically tests that cognitive control of this emotional brain center," Kash said.
And researchers traced the effect to differences in the nerve cells in the brain's prefrontal cortex. The key receptor, called NMDA, was suppressed in the mice that received alcohol.
Dr. Kash says it may be possible to design a drug to target this receptor.
The study was published in the online in the journal Nature Neuroscience.