Brain circuit links social memory to fear, triggering aversion in mice

University of Tokyo researchers identify a hippocampus–amygdala circuit that binds the memory of a familiar mouse to fear, causing avoidance after aggressive encounters; using optogenetics they could strengthen or erase this aversion, with the nucleus accumbens helping translate memory and fear into avoidance. While demonstrated in mice, the findings offer clues about how social memory and negative emotions interact, with potential relevance for anxiety and depression in humans.