Social reactivation of fear engrams enhances memory recall.

For group-living animals, the social environment provides salient experience that can weaken or strengthen aspects of cognition such as memory recall. Although the cellular substrates of individually acquired fear memories in the dentate gyrus (DG) and basolateral amygdala (BLA) have been well-studied and recent work has revealed circuit mechanisms underlying the encoding of social experience, the processes by which social experience interacts with an individual’s memories to alter recall remain unknown. Here we show that stressful social experiences enhance the recall of previously acquired fear memories in male but not female mice, and that social buffering of conspecifics’ distress blocks this enhancement.