During sleep, the brain can replay patterns associated with things we have learned. New research suggests that the hippocampus, the structure most closely associated with memory, does not need to coordinate every kind of replay.

Early-life stress can change how the brain responds to stress later in life. New research in mice points to a possible mechanism: changes in chromatin regulation may leave developing neurons biologically prepared to respond differently to future stress.

Adolescence can come with rapidly changing emotions, but some teenagers experience much more day-to-day variability than others. New research suggests that perceived stress and fluctuations in self-esteem may help explain why.