The neuropeptide oxytocin facilitates pro-social behavior and prevents social avoidance in rodents

Michael Lukas (1) , Iulia Toth (1) , Stefan O Reber (1) , David A Slattery (1) , Alexa Veenema (1) , Inga D. Neumann (1)

1 Institute of Zoology

Social avoidance and social phobia are core symptoms of various psychopathologies but their underlying aetiology remains poorly understood. Therefore, this study aims to reveal pro-social effects of the neuropeptide oxytocin, under both basal and stress-induced social avoidance conditions in rodents using a social-preference paradigm. We initially show that intracerebroventricular (icv) application of an oxytocin receptor antagonist (OTR-A) in naïve male rats (0.75µg/5µl) or mice (20µg/2µl) reduced social exploration of a novel con-specific indicative of attenuated social preference. Prior exposure of male rats to a single social defeat resulted in loss of their social preference and social avoidance, which could be restored by icv infusion of synthetic oxytocin (0.1µg/5µl) 10 min prior to the social preference test. The amygdala has been implicated in both social and oxytocin-mediated actions, but bilateral OTR-A (0.1 µg/1µl) or oxytocin (OT; 0.01 µg/1µl) administration into various subnuclei of the amygdala did not affect basal or stress-induced social preference behavior, respectively. Finally, we demonstrate the social specificity of these OT-mediated effects by showing that neither an arginine vasopressin V1a receptor antagonist (0.75µg/5µl, icv) nor the anxiogenic drug pentylenetetrazol (15mg/kg, i.p.) altered social preference while OTR-A did not affect state anxiety. Overall, the data indicate that the basal activity of the endogenous brain oxytocin system is sufficient to promote pro-social behavior in rodents while synthetic oxytocin shows potential to reverse stress-induced social avoidance and might support treatment of social phobia and social dysfunction in humans.

Mots clés: Psychiatry & Behavioral Sciences; Neuropeptides; Animal models; oxytocin; vasopressin; social defeat; amygdala; anxiety; Mood; Stress Disorders

Michael Lukas, Iulia Toth, Stefan O Reber, David A Slattery, Alexa Veenema, et al.. The neuropeptide oxytocin facilitates pro-social behavior and prevents social avoidance in rodents. Neuropsychopharmacology, 2011, ⟨10.1038/npp.2011.95⟩. ⟨hal-00652135⟩