Scientists have found a mechanism in the brain that strongly influences how much alcohol a person is likely to consume.
The mechanism is found in the cerebellum, a part of the brain at the back of vertebrate skulls, in small neurons called granule cells.
Sitting on the cells are proteins called GABAA receptors that act like traffic cops for electrical signals in the nervous system.
When activated, the GABAA receptor suppresses the firing of neurons, or brain circuits. Benzodiazepines, which enhance GABAA signalling, reduce this excitability.
Alcohol can also enhance GABAA receptor signalling and reduce firing in the brain, which is why it reduces anxiety and social inhibitions. In the cerebellum, it can lead to swaying, stumbling and slurred speech.
For the study, researchers injected a drug called THIP into the cerebellum of B6 mice.
THIP activates the GABAA receptor, recreating the effect that alcohol has on low drinking D2 mice. It ended up deterring the B6 mice from drinking.
The mechanism offers a new target for drug therapies that can curb excessive drinking.