Solidarity toward the injured is regulated by a specific region of the brain's anterior cingulate cortex (ACC), according to research in mice that reveals altruism has a biological basis. The results, presented in an article in the journal Nature, represent an advance in the understanding of helping behaviors among living beings, including human beings, highlight the authors of the research.
Until now there was scientific evidence of how individuals perceive, at a neuronal level, the pain and suffering of others. But the mechanism that causes the helping response still remains a mystery. Despite this, this research, published by a scientific team led by neurobiologist Weizhe Hong, from the University of California, Los Angeles (UCLA), sheds a little more light on the issue.
One of the clear pieces of evidence until now was that mice have prosocial responses – social behavior that benefits other people or society as a whole – when faced with the discomfort or stress of another individual. That is, they groom each other to relieve situations of tension, stress or general discomfort. With the research of Weizhe Hong and his team in Los Angeles, it is certified that rodents are capable, not only of perceiving the specific states and needs of others, but of developing certain altruistic behaviors.
The novelty of the discovery lies in the fact that there is a different neural response, depending on whether the affected person is experiencing a situation of generalized indisposition or whether they have a localized wound in the body. That is, some mice know how to distinguish between giving comfort and mitigating specific pain. “We have confirmed that the brain response to comfort someone and to help them overcome a specific problem are different. This opens the doors to knowing in depth how the rescue response works in animals and humans,” Hong tells La Vanguardia.
Researchers have found that the neurons in the brain's anterior cingulate cortex that activate when rodents watch another mouse experience an electric shock in the foot are different from those that activate when they watch another mouse in a conditioned fear situation.
They have also observed it after applying an injection to localized parts of some rodents. Immediately afterwards, some of his colleagues went to the specific area to help mitigate the pain through licking, causing a neuronal response different from that corresponding to a situation of generalized stress.
The report concludes that it is an innate response, that is, it does not require prior learning or training. “Some very young mice helped others without having ever seen a similar situation before. This is another of the most relevant findings,” highlights the research leader.
When one of the mice came to help another, the first one stopped licking itself to allow itself to be helped by the newcomer. That is to say, the injured perceived these relief actions as something beneficial that would allow them to save energy.
This differentiation in the neuronal response generates a specific behavior called healing licking. That is, the mice not only lick the wounds of those affected to clean and disinfect the area, but they also do so with the aim of reducing pain on a psychological level. According to Hong, these actions “not only allow saliva to perform its disinfectant function, but it also has a strong emotional component that helps calm the injured person.”
Despite these results, understanding how helping behavior works “still remains one of the great enigmas of neuroscience,” Hong concludes. “Our study advances the understanding of how the brain represents the negative states of others and regulates the expression of appropriate helping behaviors to address specific states and needs. “These advances could help in the development of interventions that promote altruistic behaviors, not only in an animal community, but in human society.”
Regarding the extrapolation of these results to human beings, Hong highlights that “despite not knowing if exactly the same thing happens, everything points in the same direction. These results establish the basis for knowing what really happens in our brain when someone requires our help. It opens the door to understanding much more about what happens in the anterior cingulate cortex, in how we transform helping stimuli into helping actions,” she concludes.
