We're all aware heavy drinking can stress relationships, but who knew that applies to non-human species as well? In news you didn't think you needed to hear, but really, really do, male prairie voles' alcohol consumption can harm their intimate relationships. This isn't just a case of scientists chasing an Ig Nobel award, however. The same research has provided pointers into how alcohol affects specific parts of the human brain.
"We know that in humans, heavy drinking is associated with increased separation rates in couples in which one of the partners is a heavy drinker and the other is not, while separation rates don't seem to increase when both partners drink in a similar manner, or don't drink at all," said Professor Andrey Ryabinin of Oregon Health and Science University in a statement.
Without recording if anyone was drunk at the time, Ryabinin and colleagues decided to see if the same thing applied to non-human mammals, using the humble prairie vole. It's not just that voles are both social animals and largely monogamous that makes them suitable for this study. They are also an exception to Ryabinin's observation that “Not many rodents like to drink alcohol.”
Voles can't brew their own alcohol of course, but graduate student Andre Walcott gave male voles 10 percent alcohol solution. Some female partners were also given alcohol, while others were restricted to water. Control vole couples were both kept on water.
Then Walcott introduced a new female to the cage and watched to see how much time males spent with the new female compared to existing partners.
In Frontiers in Psychiatry, Ryabinin and Walcott report that the words of Gretchen Phillips – “If a woman don't drink beside her man, then she will surely lose him” – apply to voles. It wasn't drinking that led male voles to stray, but drinking alone.
The finding removes both the social aspects of human alcohol consumption – men who drink without their partners are probably spending time in bars socializing with others – and the effects that might be explained by active choices to abstain.
Before anti-science politicians rush to decry a perceived lack of practical value, the authors also found differences in the brains of males who drank alone from those who drank with their partners. These were focused in a region called the periaqueductal grey, providing a potential focus for human research.
"In future studies, we might be able to find strategies to overcome the negative effects of alcohol, to improve relationships that are disrupted by problematic drinking,” Ryabinin said.
That's great and all, but we have other questions: What happens when it's the female vole drinking alone? Are same-sex vole couples also affected? How did this trait evolve?