The roots of empathy: Through the lens of rodent models

- Rodents are capable of emotional contagion to both painful and fearful stimuli.
- Rats and mice respond to unpleasant vicarious experiences with activation of amygdala, prefrontal and anterior cingulate cortices.
- Rats display pro-social behaviors towards conspecifics in need.
- Familiarity and physical similarity modulate empathic behaviors.
- Stress level and sex influence the ability to share emotions.

Empathy is a phenomenon often considered dependent on higher-order emotional control and an ability to relate to the emotional state of others. It is, by many, attributed only to species having well-developed cortical circuits capable of performing such complex tasks. However, over the years, a wealth of data has been accumulated showing that rodents are capable not only of sharing emotional states of their conspecifics, but also of prosocial behavior driven by such shared experiences. The study of rodent empathic behaviors is only now becoming an independent research field. Relevant animal models allow precise manipulation of neural networks, thereby offering insight into the foundations of empathy in the mammalian brains. Here we review the data on empathic behaviors in rat and mouse models, their neurobiological and neurophysiological correlates, and the factors influencing these behaviors. We discuss how simple rodent models of empathy enhance our understanding of how brain controls empathic behaviors.