Neural mechanisms underlying orofacial prosocial behavior in rodents

Social behavior is a highly complex process that requires appropriate response to social cues and is fundamental to the survival, reproduction, and well-being. Orofacial behavior, which refers to the dynamic movements and configurations of the mouth, lips, and jaw, is an evolutionarily conserved behavior present in both humans and animals. Rodents engage in a multitude of well-coordinated orofacial prosocial behaviors, such as vocalizing, sniffing, helping or rescuing, licking, and pup retrieval, which play critical roles in communication, emotion, and social affiliation. However, there still lack integrative frameworks that explain how these evolutionarily conserved motor actions are implemented at the neural circuit level and how they contribute to broader prosocial functions relevant to social behavior research and social deficits. In this review, we summarize recent advances in understanding the neural basis that trigger the expression of orofacial prosocial behavior in animal studies, particularly in rodents. • The PVT→NAcSh and oxytocin-associated hypothalamic circuits mediate rescue-like behaviors. • The PAG-centered networks coordinate ultrasonic vocalizations in social contexts. • The ACC activity governs empathy-related social licking behavior. • Respiratory–motor coupling coordinates vocalizing, licking, and sniffing. • The mPOA orchestrates pup retrieval behavior via VTA and PAG projections.