Empathic behavior according to the state of others in mice

Introduction: Empathic behavior is essential for social activities in social animals. Therefore, lack of empathy is a feature of several neuropsychiatric disorders. However, the underlying mechanisms of empathy and which animals possess it remain unclear. In this study, we investigated whether mice show empathic behavior. Methods: We tested mice for empathy-like behaviors toward conspecifics who were distressed. We investigated behavioral changes in cage-mate or stranger mice. Results: When the conspecific mice were in a painful state, subject mice showed preferential approach behavior toward them, presumably recognizing the state. Both visual information and olfactory information are indispensable for this empathic behavior. Conclusions: These results suggest that the mouse recognizes the emotional state of the conspecific and engages in social interaction. The results of this study are useful for the elucidation of the causal mechanisms involved in neuropsychiatric disorders and may contribute in the development of novel treatment targets.