DECODING MALADAPTIVE DECISION-MAKING AFTER SOCIAL STRESS

Rapid threat recognition supports survival, but repeated aggression can promote fear generalization that disrupts adaptive social behavior. Rodent social defeat paradigms reliably induce chronic avoidance, yet the early transition from acute social fear to persistent maladaptive withdrawal – and its circuit mechanisms – remains poorly resolved. The nucleus accumbens (NAc), which integrates social reward and threat signals, is well positioned to mediate this shift.
We hypothesize that brief social stress triggers NAc neuroadaptations that bias social decision-making from approach to persistent avoidance via recruitment of distinct, activity-defined neuronal ensembles.
Using an adapted sub-chronic social defeat protocol, we find that brief repeated exposure is sufficient to induce generalized social avoidance toward novel, unfamiliar juveniles, reflected by reduced social interaction time relative to controls, whereas a single day of defeat does not elicit significant avoidance. Using in vivo fiber photometry, we have quantified neuromodulator dynamics during the emergence of avoidance behavior. Ongoing ex vivo patch-clamp electrophysiology and activity-dependent tagging (TRAP) are being used to identify and functionally characterize stress-recruited NAc neuronal populations.
Defining how brief aggression exposure reshapes NAc ensemble recruitment and neuromodulatory signaling will reveal mechanisms by which acute stress can precipitate persistent social withdrawal.