A recent study published in PNAS reveals that mice exhibit instinctive rescue-like behaviors towards anesthetized peers, suggesting that prosociality may be biologically hardwired in mammals.

This research challenges the belief that altruistic behaviors are exclusive to cognitively advanced species, indicating that even small mammals like mice possess innate prosocial tendencies.

Researchers identified oxytocin as a crucial factor in these behaviors, activating two brain pathways that coordinate emotional and motor responses during helping actions.

Led by Dr. Hu Li and Dr. Chen Zhoufeng, the study demonstrates that oxytocin triggers circuits in the amygdala and stria terminalis, facilitating altruistic actions such as licking and grooming.

The first pathway, through the central amygdala, processes the emotional aspects of distress, while the second pathway through the dorsal bed nucleus of the stria terminalis facilitates the physical actions of helping.

When placed with anesthetized peers, observer mice displayed signs of stress, indicated by elevated blood corticosterone levels, which prompted them to engage in allogrooming behaviors that aided the recovery of the anesthetized mice.

These helping behaviors not only accelerated the recovery of the distressed peers but also reduced the stress levels of the observer mice, suggesting a mutually beneficial dynamic.

The researchers employed advanced techniques, including transgenic mice and chemogenetics, to uncover the neural mechanisms behind these responses.

The findings provide a foundation for future research into the neurobiology of empathy and complex social interactions, highlighting the evolutionary significance of altruism.

Oxytocin neurons in the paraventricular nucleus of the hypothalamus are activated by distress signals from peers, leading to the release of oxytocin that acts on two parallel pathways to coordinate the emotional and motor components of rescue behavior.

This study underscores the importance of oxytocin in activating brain pathways that facilitate altruistic behaviors, furthering our understanding of social interactions in mammals.