A team of researchers at the Medical University of South Carolina has found that deactivating a stress-signaling system in a brain area known for motivation and emotion-related behaviours decreases binge drinking. The mouse study, which was published in the May issue of Neuropharmacology, identified a particular system in a specific brain region that can be manipulated to reduce harmful binge drinking.
Previous studies have demonstrated the involvement of kappa opioid receptors in binge-like drinking in mice. The current studies examined the role of kappa opioid receptors in a specific brain region in binge-like alcohol consumption in male and female mice. The brain region was bed nucleus of the stria terminalis (BNST), which is a heterogeneous and complex limbic forebrain structure that plays an important role in controlling autonomic, neuroendocrine and behavioural responses. Its control of physiological and behavioural activity is mediated by local action of numerous neurotransmitters.
The research found that direct administration of a long lasting kappa opioid receptors antagonist, into the BNST decreased binge-like alcohol consumption and blood alcohol concentrations in male and female mice. Similarly, the direct administration of the kappa opioid receptors antagonist into the BNST also modestly reduced binge-like sucrose consumption.
Further, the study also administered a kappa opioid receptors agonist which resulted in a robust increase in alcohol intake. This increase in alcohol intake was subsequently blocked by administration of the kappa opioid receptors antagonist in the BNST.
The researchers conclude that together, these data suggest that kappa opioid receptors activity in the brain’s bed nucleus of the stria terminalis contributes to binge-like alcohol consumption in both male and female mice. This finding brings researchers closer to understanding which signals in the brain drive individuals to consume alcohol excessively and put them at risk for developing an alcohol use disorder.
Source: Harold L. Haun, William C. Griffin, Marcelo F. Lopez, Howard C. Becker. Kappa opioid receptors in the bed nucleus of the stria terminalis regulate binge-like alcohol consumption in male and female mice. Neuropharmacology, 2020; 167: 107984.