Brain region linked to preference for alcohol over social rewards

People with alcohol use disorders tend to prioritize alcohol over alternative rewards, and the neural underpinnings of this are unclear. New from JNeurosci, researchers led by Nathan Marchant, from Amsterdam Medical University Center, used rats to explore the role of a brain region involved in planning and making decisions in pursuing alcohol or socializing with peers. 

After training rats to lever press for alcohol and social reward, the researchers discovered that rats favored alcohol over other reward options. Furthermore, the brain region of interest-the anterior insula-was more active during alcohol-related actions than social behavior. This was especially true during the time period just prior to making a decision about these actions. A mathematical model suggested that alcohol-related activity in the anterior insula correlated with how quickly rats made choices about alcohol after their preference for alcohol was established. 

According to the researchers, this work suggests that the anterior insula may encode a bias in the decision-making process to support selecting alcohol over other rewards. Elaborating on the clinical relevance, says Marchant, "The reason we do this type of modeling is so we can decompose decision-making into variables that can explain how rats make decisions. This same approach could be applied to humans with alcohol use disorder to help decipher if signals from this brain region are involved in their maladaptive decision-making."