Extinction of fear is facilitated by social presence: Synergism with prefrontal oxytocin

• This study addresses if extinction can be modified by social presence and the role of prefrontal oxytocin in mediating the effects.
• The results show that extinction is enhanced by social presence.
• The results show that the effect is mediated by oxytocin as microinfusion of the agonist for oxytocin into the mPFC enhanced extinction.
• Oxytocin antagonist impaired extinction and reversed the enhancing effect of pairing on extinction.
• The results show for the first time that social presence of another animal that was conditioned to the conditioning box enhanced extinction and that this effect is mediated by prefrontal oxytocin.

This study addressed the question of whether extinction in pairs would have a beneficial effect on extinction of fear conditioning. To that end, we established an experimental setting for extinction in which we trained animals to extinguish contextual fear memory in pairs.Taking advantage of the role of oxytocin (OT) in the medial prefrontal cortex (mPFC) in the mediation of memory extinction and social interaction, we also sought to study its role in social interaction-induced effects on extinction. Our results clearly show that the social presence of another animal in the extinction context facilitates extinction, and that this facilitation is mediated through mPFC–OT. Our results suggest that social interaction may be a positive regulator of fear inhibition, implying that social interaction may be an easy, accessible therapeutic tool for the treatment of fear-associated disorders.