A neural basis for prosocial behavior toward unresponsive individuals

Humans often take actions to assist others experiencing unresponsiveness, such as transient loss of consciousness. How other animals react to unresponsive conspecifics-and the neural mechanisms driving such behaviors-remain largely unexplored. In this study, we demonstrated that mice exhibit rescue-like social behaviors toward unresponsive conspecifics, characterized by intense physical contact and grooming directed at the recipient's facial and mouth areas, which expedite their recovery from unresponsiveness. We identified the medial amygdala (MeA) as a key region that encodes the unresponsive state of others and drives this head-directed physical contact. Notably, the behavioral responses toward unresponsive conspecifics differed from those directed at awake, stressed individuals, and these responses were differentially represented in the MeA. These findings shed light on the neural mechanisms underlying prosocial responses toward unresponsive individuals.