Male mice show higher alcohol intake after social isolation, study finds

Researchers led by Risha Patel at Northwestern University report that social isolation makes a neural pathway between the amygdala and prefrontal cortex more active in male mice — and that change is associated with a stronger drive to drink alcohol.

Gender-specific neural response

In the experiments, animals that had previously been group-housed were moved to isolation and later offered a choice between two drinking bottles: plain water and a 15 percent alcohol solution. After the isolation period, male mice chose the alcohol more often, while females decreased their alcohol intake.

Patel explained the neural finding in plain terms: "Our research shows that a specific signaling pathway becomes overactive during isolation and directly leads to increased alcohol consumption, and that males and females resort to different neuronal strategies when alone," she said. The team links that overactivity to strengthened communication between the amygdala and prefrontal cortex.

The authors note that similar brain circuits have been implicated in human craving and relapse, and that clinical work points to the prefrontal cortex as an important player in those processes. They caution, however, that how directly results from mice translate to people remains an open question and will require further study.

Complementing the animal work, an analysis published last year of roughly 17,800 participants across three large German studies found that lonely men were more likely to drink frequently and to face related health risks; lonely women, by contrast, were less likely to consume alcohol than women who did not report loneliness.

The researchers say the new findings could help frame future research into mechanisms behind problematic alcohol use, and stress that follow-up studies are needed to determine whether targeting the identified circuit would alter drinking behavior in humans.

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