A recent study has found that when a mouse discovers a companion losing consciousness, it seems to use actions similar to first aid to awaken it. The research indicates that caring behaviors in the animal kingdom may be more common than previously imagined, suggesting that helping others may be deeply ingrained in the genetics of mammals.
According to a report by National Public Radio (NPR), Li Zhang, a neuroscientist at the University of Southern California, began to notice a few years ago that sometimes when he placed an anesthetized mouse back into the cage in the laboratory, its cage mate would exhibit strange behaviors such as sniffing around its face or biting its face.
For Zhang, that mouse seemed to be attempting to help the unconscious companion wake up through a form of first aid. Scientists have also observed this behavior in other animals such as elephants or dolphins, as they assist incapacitated members of their species.
Zhang mentioned that while other researchers had previously noticed similar rescue-like behaviors towards unconscious mice, it had never been studied in detail before.
Today, research conducted by Zhang and colleagues proves that unconscious mice can trigger a series of behaviors in their cage mates, which appear to accelerate the recovery of the anesthetized mouse.
They found that the test mice initially sniffed and groomed the anesthetized companion. However, if the anesthetized mouse still showed no response, the test mouse would start to bite its mouth, and even pull out its tongue, as if clearing its airway.
Zhang told New Scientist magazine, “They start with sniffing, then grooming, and then very intense physical interactions. They really opened the mouth and pulled out the tongue.”
Further physical interactions include licking the eyes and biting around the mouth area. In more than half of the cases, after focusing on the companion’s mouth, the test mouse pulled out the companion’s tongue.
In another test, researchers gently placed a non-toxic plastic ball into the mouth of the unconscious mouse. In 80% of cases, the test mouse successfully removed the object.
The report’s lead author, another neuroscientist at the university, Huizhong Tao, mentioned, “If the observation time is extended, perhaps the success rate will be higher.”
Researchers found that among the various “first aid” behaviors exhibited by the test mice, pulling out the tongue was the most effective, as it could widen the airway of the unconscious mouse, evidently providing assistance.
They also discovered that if the test mice were familiar with the unconscious mouse, they spent more time on “first aid” compared to mice they had never encountered before.
James Burkett, a neuroscientist at the University of Toledo not involved in the study, stated that this familiarity difference indicates that the mice’s “first aid” behaviors are not reflex actions, but are responses made after considering the situation and the identity of the other party.
Zhang and his colleagues found that these behaviors are driven by neurons releasing oxytocin in the amygdala and hypothalamus regions of the brain. Oxytocin, a hormone involved in various caring behaviors in vertebrates.
They believe that this behavior is innate rather than learned, partly because all the mice tested were only 2 to 3 months old and had not seen this behavior before or encountered an anesthetized companion in the cage.
Zhang stated that this innate behavior plays a role in enhancing group cohesion and may be more widespread among social animals than previously observed.
The results of the above study were published in the journal Science on February 21st.