The hippocampus is an area of the brain that plays an important role in learning and memory. Several studies have shown that alterations occur in the hippocampus following exposure to stress. Other brain areas involved in memory, including the amygdala and prefrontal cortex, are involved in the mediation of the stress response. The severe stress of exposure to a traumatic event may result in posttraumatic stress disorder (PTSD); patients show evidence of memory disturbance, including intrusive thoughts, flashbacks, nightmares, and problems with memory and concentration. Alterations in these brain areas provide a biological basis for the memory-related symptoms of PTSD. This entry focuses on the hippocampus.

Exposure to stress has been associated with damage to neurons in the hippocampus. Numerous studies in animals have demonstrated biological ...