Scientists 'really surprised' after gene-editing experiment unexpectedly turn hamsters into hyper-aggressive bullies

• A team of neuroscientists was "really surprised" by the results of a gene-editing experiment on hamsters.
• The team expected that the elimination of vasopressin activity would make the hamsters behave more peacefully.

A team of neuroscience researchers was left "really surprised" after a gene-editing experiment unexpectedly created hyper-aggressive hamsters, according to a statement by Georgia State University (GSU).

The GSU research, published in Proceedings of the National Academy of Sciences (PNAS), set out to find more about the biology behind the social behavior of mammals.

The scientists used Syrian hamsters and CRISPR-Cas9 — a revolutionary technology that makes it possible to turn on or off genes in cells. The technology knocked out a receptor of vasopressin — a hormone associated with enhanced aggression.

The scientists anticipated that doing so would "dramatically" alter the social behavior of the Syrian hamsters, making them more peaceful. It did change their behavior, but not how they had expected.

"We were really surprised at the results," said the study's lead author, GSU professor H. Elliott Albers, in the university's statement.

"We anticipated that if we eliminated vasopressin activity, we would reduce both aggression and social communication," Albers continued. "But the opposite happened."

The hamsters without the receptor displayed "high levels of aggression" towards hamsters of the same sex compared to their counterparts with the receptors intact, the study said.

"This suggests a startling conclusion," Albers said, per the statement. "Even though we know that vasopressin increases social behaviors by acting within a number of brain regions, it is possible that the more global effects of the Avpr1a receptor are inhibitory."

The "counterintuitive findings" show that the scientists "don't understand this system as well as we thought we did," Albers said.

Developing gene-edited hamsters was "not easy," Albers went on. He added that a better understanding of the role of vasopressin in social behavior is vital to helping scientists identify new treatment strategies for psychiatric disorders in humans, ranging from autism to depression.