It seems alcohol makes the heart grow fonder, if you're a female prairie vole. Researchers have found for the first time that alcohol affects the brain systems involved in social bonding differently for males and females.

The study was published Monday, April 7, in the journal Proceedings of the National Academy of Sciences.

Because prairie voles are known to mate for life, both in the wild and the lab, the rodents are often used as a model to understand the neurochemistry in human brains that leads us to form lifelong relationships.

The small fuzzy creatures also make useful lab models of human addiction behavior due to their social nature and taste for alcohol (they even prefer it over water).

A boozy encounter

In this study, female and male voles were partnered up and given access to tubes containing ethanol and water or only water. After 24 hours of hanging out together, the paired prairie voles were separated and moved to different cages. Later, the researchers tested their "preference" for either their drinking mate or an unknown vole.

The alcohol affected the females differently than males.

The authors found that the alcohol made the females more likely to pair-bond with their drinking partner than the females that only drank water. Conversely, alcohol made the males less likely to bond with their original partner after the boozy episode.

These differences in behavior seemed to be dictated by changes in the brain to systems involved in social and anxiety-like behaviors — the same ones that dictate the formation of the voles' monogamous relationships.

The researchers note in the paper that the lower likelihood of males to pair-bond when drinking is reminiscent of the negative effects of alcohol on long-term attachments and marital happiness in humans — suggesting that there could be a biological element at play.

"These findings allow us to understand the factors involved in regulations of social behaviors, and the effects of alcohol on them, better," the study authors wrote in their paper. "Identification of these factors can help develop better ways to prevent or treat the devastating effects of alcohol abuse on social relationships."