Animal rights activists lashed out Wednesday at Oregon Health & Science University about an experiment that tested the effect alcohol has on prairie vole couples.

The animals are monogamous and will consume alcohol, a rarity among rodents.

The experiment aimed to mimic human relationships and determine whether the effect of alcohol on the brain caused a breakdown in relationships.

The researchers found that when both male and female prairie voles had alcohol, the males stuck to their mates. But male prairie voles who drank while their partner did not were more likely to wander.

The research was conducted at the Portland VA Health Care System, which is next to OHSU's main campus in Southwest Portland. It was led by a behavioral neuroscientist who has dual appointments at OHSU and the VA.

The experiment angered PETA, an animal rights group, which sent a letter Wednesday to OHSU asking why "these bizarre, pointless and deadly experiments were given institutional approval."

OHSU responded with a statement, saying in part that its animal experiments help develop "new ways to identify, prevent, treat or eradicate disease and to improve human and animal health. OHSU's views on this topic reflect those of other academic health centers, universities, physicians and scientists throughout the world."

The statement said the findings could lead to treatments to "prevent or possibly reverse the negative effects of alcohol in humans." It said that would help improve human relationships shattered by drinking.

The research, published this month in the journal Frontiers of Psychiatry, involved 150 prairie voles that were mated for a week. They were then separated with a mesh that allowed them to smell each other and interact. The pairs were divided into three groups. One was only offered water to drink. The second had both water and alcohol. In the third group of pairs, only the male had a choice of water and alcohol while the female only had water.

The males in that last group spent much less time with their partners than their peers in the other two groups.

PETA called the experiment "arbitrarily created" and not one that models human partnerships.

"Vole biology doesn't mirror human biology and these experiments are nothing more than a curiosity driven boondoggle with a serious body count," PETA science adviser Frances Cheng said in a statement.

PETA complained that the voles were kept in cramped, plastic housing then killed after the experiment. The study said the pairs were placed in "standard plastic housing" cages.

The female voles were euthanized after the study and analyzed along with their embryos.

OHSU said its animals are well cared for by a licensed veterinarian and overseen by a special committee as required under U.S. law.

The study was funded by two grants from the National Institutes of Health.

-- Lynne Terry