Brain protein tied to binge drinking
Researchers from the Scripps Research Institute have found that a particular brain protein appears to play a key role in controlling binge drinking.
In their study, published in _Proceedings of the National Academy of Sciences, _they determined that removing the gene for this protein in mice led to more excessive alcohol consumption and inhibited the brain from signaling its reward center. In short, it appeared that the mice needed to drink more to experience the reward associated with alcohol consumption.
The protein is part of the "G protein-gated inwardly rectifying potassium channel" or GIRK family. GIRK channels run throughout the nervous system and reduce the sensitivity of neurons so they don’t fire as often. It had previously been proven that alcohol directly triggers GIRK channels, but it was not cclear how thie affected behavior.
For the study, researchers honed in on GIRK3, previously known to influence other drugs’ reactions, such as cocaine. Mice with GIRK3 were compared to mice engineered without GIRK3. The latter mice did not show the typical signs of alcohol withdrawal, such as shaking. There were also differences in how alcohol was consumed. In a mock happy hour, the two groups of mice were allowed to drink ethanol for only two hours a day. During this two-hour period, the mice without GIRK3 consumed much higher amounts of alcohol than the control group. But when alcohol was not provided with a time restriction and served all day, the mice without GIRK3 did not drink to excess.
Overall, the researchers found that removing GIRK3 did not affect baseline activity. But when alcohol was introduced, there was a notable difference. Mice without GIRK3 had a pathway that was unresponsive to the effects of alcohol. Without GIRK3, the release of dopamine was also not triggered.
When GIRKs was reintroduced in the mice, they were able to reduce their binge-drinking habits. More research is needed to determine if this approach could lead to a treatment for binge-drinking humans.
According to the U.S. Centers for Disease Control and Prevention, binge drinking -- defined as drinking to the point of intoxication -- puts people at greater risk for health problems such as cardiovascular disease, liver disease and neurological damage.