Differential effects of social defeat in rats with high and low locomotor response to novelty

▶HR rats show less passive-submissive behavior than LRs during social defeat. ▶Social defeat increases immobility in the forced swim test in HR rats only. ▶HR rats show higher CORT levels than LRs during recovery from social defeat. ▶Social defeat significantly decreases thymus weight in HR animals only. ▶Social defeat decreases MR/GR ratio in the hippocampus of HR but not LR rats.