Proximity in mice induced by an auditory-conditioned stimulus.

Social affiliation promotes survival and well-being across species, and proximity to conspecifics is a necessary precondition for affiliative contact. While innate threats reliably increase proximity among conspecifics, whether learned threats have the same effect remains unknown. Here, we report that an auditory conditioned stimulus (CS) induces proximity in mice. In same-sex dyads, fear-conditioned mice increased proximity during CS presentation, independent of freezing levels. This CS-evoked proximity required familiarity between partners and intact basolateral amygdala-to-ventral hippocampus inputs, demonstrated by DREADD-mediated suppression. It also required oxytocin receptor signaling, demonstrated by systemic administration of the antagonist L368,899. These findings suggest that learned and innate threats engage shared neural circuitry for social proximity.