Serotonin-producing neurons in the brainstem release serotonin throughout the brain during moments of novel social encounters. The release of serotonin stimulates neurons in the medial septum via a subtype of serotonin-sensitive receptor molecules. Blocking the release of this receptor molecule prevents the formation of new social memories.
A new study reports the CA2 region of the hippocampus controls both higher order cognition, like social memory, and instinctual behaviors, such as aggression. The findings could shed light on why abnormal social behaviors may occur in schizophrenia and other psychiatric illnesses.