Early life stress modulates social behavior via oxytocin and arginine vasopressin in males.

Social behaviors are essential for both reproduction and survival. Human and animals exhibit distinct patterns of social interaction following trauma experienced during puberty, which are shaped by the complex interplay between environmental and biological factors. Although neuropeptides and early life stress (ELS) influence social behavior, it remains unclear whether the regulation of neuropeptides in response to ELS further modulates social behavior. Two sex neuropeptides, oxytocin (OT) and arginine vasopressin (AVP), exert profound effects on social behaviors. Therefore, we investigate the involvement of OT and AVP in modulating the alterations in social behavior resulting from ELS. The 89 adult men participants were divided into heterosexual (n=32) and gay/bisexual (n=57) groups. Mental health and the serum levels of OT and AVP were evaluated. Our clinical samples reveal significant variations in ELS exposure across sexual orientation groups, which correlate with neuroendocrine alterations, including altered OT and AVP levels. Animal study further substantiates the critical role of OT and AVP in mediating these changes, highlighting their involvement in shaping social behavior. These findings uncover potential underlying mechanisms through which the OT and AVP systems contribute to stress-induced alterations in social behavior.