Lab Mice Appear to Offer ‘First Aid’ Care to Their Unconscious Companions, Even Pulling on Their Tongues
A new study finds that mice will sniff, lick and pull the tongue of other mice that are under anesthesia, serving to open their airways
/https://tf-cmsv2-smithsonianmag-media.s3.amazonaws.com/accounts/headshot/Sara_-_Headshot_thumbnail.png)
Humans aren’t the only animals that give first aid. Some ants secrete antibiotics for their nest mates with injuries. Elephants, dolphins and chimpanzees have all been observed touching and nudging incapacitated individuals.
Now, neuroscientists at the University of Southern California have observed laboratory mice appearing to do the same for their unconscious cage mates. Their findings were published in the journal Science on Friday.
The researchers conducted a series of tests that involved presenting mice with two companions: a familiar cage mate that was under anesthesia and another mouse that was conscious and moving around. They found that the mice spent most of their time with the unconscious creature—and that they showed similar patterns of behavior when caring for it.
“They start with sniffing, and then grooming, and then with a very intensive or physical interaction,” says Li Zhang, the senior author of the study, to New Scientist’s Chris Simms.
The mouse would then open its companion’s mouth and, in more than 50 percent of cases, start pulling on its tongue. The research suggests this behavior serves to open the animal’s airways or dislodge objects in its throat: When the team placed a non-toxic object in the mouth of the unconscious mouse, the tongue-pulling removed it 80 percent of the time.
Mice were more likely to perform these first aid-like behaviors on other individuals that they were familiar with, rather than strangers. Once the unconscious mouse woke up, its carer would stop its aid. Additionally, anesthetized mice that received care from other rodents tended to wake up sooner than those that were left alone.
These helping behaviors are driven by oxytocin-releasing neurons in the brain, the study found. The hormone is also involved in caring behaviors in other animals. “That was a really well done part of the study, showing that this is engaging social behavior networks in the brain,” says James Burkett, a neuroscientist at the University of Toledo who wasn’t involved in the research, to Jonathan Lambert at NPR.
“To me, this looks very much like a behavior that’s driven by what I would call the altruistic impulse,” Burkett adds to NPR. “We can’t infer just from our observations that these mice have an intention to help. We only know that they’re responding to an animal in need and they perform a behavior that does benefit them.”
Two other recent studies have reported similar behaviors in mice, adding strength to the idea that the animals might have an impulse to help others.
“I have never observed these types of behaviors when we run experiments in the lab, but we never placed a recovering animal with a partner until they were fully awake,” says Cristina Márquez, a researcher at the Center for Neuroscience and Cell Biology in Portugal, to New Scientist. “The fact that three independent laboratories have observed similar behaviors indicates that this is a robust finding.”
Not all scientists are convinced, however, that the mice intend to help each other. “If I drop twenty dollars, by mistake, on the street and someone else picks it up, that person has been helped, but I have not helped them,” says Peggy Mason, a neuroscientist at the University of Chicago who wasn’t involved in the study, to NPR. “They found a great behavior; I don’t dispute that. I dispute the interpretation of it.”
Márquez also tells New Scientist that “we should be really careful about anthropomorphizing too much what we observe in non-human species or attributing intentions that go beyond what is observed.”
