The two brain areas – the extended amygdala and the ventral tegmental area – have been implicated in alcohol binge drinking in the past.
However, this is the first time that the two areas have been identified as a functional circuit, connected by long projection neurons that produce a substance called corticotropin releasing factor (CRF).
The results, published online March 3, 2016 in the journal Biological Psychiatry, provide the first direct evidence in mice that inhibiting a circuit between two brain regions protects against binge alcohol drinking.
“The puzzle is starting to come together, and is telling us more than we ever knew about before,” Dr. Thiele said.
“We now know that two brain regions that modulate stress and reward are part of a functional circuit that controls binge drinking and adds to the idea that manipulating the CRF system is an avenue for treating it.”
In their study, Dr. Thiele and co-authors show that alcohol activates the CRF neurons in the extended amygdala, which directly act on the ventral tegmental area.
These observations in mice suggest that when someone drinks alcohol, CRF neurons become active in the extended amygdala and act on the ventral tegmental area to promote continued and excessive drinking, culminating in a binge.
“The findings may shed light on future pharmacological treatments that may help individuals curb binge drinking and may also help prevent individuals from transitioning to alcohol dependence,” Dr. Thiele said.
“It’s very important that we continue to try to identify alternative targets for treating alcohol use disorders.”
Jennifer A. Rinker et al. Extended Amygdala to Ventral Tegmental Area Corticotropin-Releasing Factor Circuit Controls Binge Ethanol Intake.Biological Psychiatry, published online March 3, 2016; doi: 10.1016/j.biopsych.2016.02.029