Scientists Accidentally Turn Hamsters into Hyper-Violent Monsters

  • We’re pretty sure we’ve seen a disaster movie with this exact plot.

Just last week we reported on a dead hamster that saved a Singaporean man from death row. Had it been one of these hamsters, it probably would’ve gnawed the man to death on its own.

In what sounds like the plot of a B-class horror movie, scientists were messing with the genome of Syrian hamsters. But their experiment went awfully wrong.


Using gene therapy, the researchers attempted to make the hamsters friendlier and more docile. Yet they became everything but — the hamsters turned into ultraviolent psychopaths that attacked everything in sight.

“We were really surprised at the results,” said H. Elliott Albers, a Regents’ Professor of Neuroscience at Georgia State University and one of the study’s lead authors.

So, when the monster hamsters break free and wipe out human civilization, you know who to blame.

“The hell are you looking at? Want a piece of me, punk?”

Crisp Hamster Genes

The new study, published in the journal Proceedings of the National Academy of Sciences, had innocent enough aims. The researchers wanted to research major neurochemical signaling pathways and understand the resulting social changes.

In plainer terms, they wanted to see how switching off the brain’s ability to process certain chemicals would affect social behavior. We suppose you can still call that “innocent enough.”

The research team chose to carry out the experiment on Syrian hamsters. Believe it or not, the tiny rodents are very important for the study of social behaviors and communication.

The social order of a horde of hamsters (yes, that’s the official word) is surprisingly similar to that of humans. Add to that the fact that we know their full genome, and they make for a good platform for studying social phenomena.

For this study, the researchers turned off the hamsters’ brain receptors processing vasopressin. It plays an important role in regulating, among other things, social communication, aggression, and sexual motivation.

To inhibit the hormone receptors, the scientists used CRISPR-Cas9 technology. CRISPR is a common technology for gene editing.

Sometimes referred to as “molecular scissors,” CRISPR allows researchers to cut DNA at specific locations. They can then renew or replace genes as necessary.

Essentially, CRISPR makes it possible for scientists to remove or add genetic material, or turn certain genes on or off. And that’s what they did with the hamsters.

Equal Opportunity Violence

Granted, the research team had expected the hamsters’ behavior to change dramatically. But they had theorized that removing vasopressin from the equation would create a peaceful hamster society.

“We anticipated that if we eliminated vasopressin activity, we would reduce both aggression and social communication,” said Albers.

But that’s not at all what happened. In fact, the results were the exact opposite.

With vasopressin receptors shut down, the hamsters became real chatterboxes. They started communicating exponentially more with their litter mates.

At the same time, the hamsters became extremely aggressive. Without vasopressin, even the generally strict gender difference in aggression broke down.

With normal, untampered hamsters, male hamsters are feistier than females, especially towards other males. But with vasopressin eliminated, all hamsters started fighting with others of the same sex.

That’s one kind of gender equality, we suppose.

We Now Know What We Don’t Know

So, what did we learn from this study? According to the researchers, the main value of the psycho hamsters is in highlighting how much we don’t know.

With gene editing becoming more common, Alders said this study underlines how even small genetic changes can cause widespread, surprising effects. In this case, the thing we don’t understand is brain chemicals’ effect on social behavior.

“We don’t understand this system as well as we thought we did. The counterintuitive findings tell us we need to start thinking about the actions of these receptors across entire circuits of the brain and not just in specific brain regions,” he explained.

Alders’ team now wants to use their findings to further study vasopressin’s effects on aggression. In the long run, knowing how such systems work could help us provide better care for people suffering from mental conditions.

“Developing gene-edited hamsters was not easy, but it is important to understand the neurocircuitry involved in human social behavior and our model has translational relevance for human health,” said Alders.

“Understanding the role of vasopressin in behavior is necessary to help identify potential new and more effective treatment strategies for a diverse group of neuropsychiatric disorders ranging from autism to depression,” he added.

That’s all well and good, as long as they’re careful if they start implementing these findings in humans. We’d hate to see the psycho hamster scenario play out with people.

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