Neuro-Immune Mechanisms Regulating Social Behavior: Dopamine as Mediator?

Social interactions are fundamental to survival and overall health. The mechanisms underlying social behavior are complex, but we now know that immune signaling plays a fundamental role in the regulation of social interactions. Prolonged or exaggerated alterations in social behavior often accompany altered immune signaling and function in pathological states. Thus, unraveling the link between social behavior and immune signaling is a fundamental challenge, not only to advance our understanding of human health and development, but for the design of comprehensive therapeutic approaches for neural disorders. In this review, we synthesize literature demonstrating the bidirectional relationship between social behavior and immune signaling and highlight recent work linking social behavior, immune function, and dopaminergic signaling in adolescent neural and behavioral development. Immune challenges impair social behavior by altering neuro-immune signaling in brain regions important for reward/motivation. Social context influences immune function. The dopaminergic reward circuitry is engaged during social behaviors and impacts immune function. Microglia and immune signaling play a critical role in the developmental organization of dopaminergic neural circuitry and social behavior development during adolescence. Adolescent neural and behavioral development may represent an ideal model in which to ask questions regarding social-immune interactions in health and disease.