The hippocampus is a pair of small structures in the brain that is located within the medial temporal lobe. Along with its associated structures, it plays a role in emotion, behavior, long term memory, the sense of smell and spatial navigation. It was named by a 16th-century anatomist who believed it resembled a sea horse (Greek "hippo" = "horse").
The hippocampus can be damaged by Alzheimer's disease, hypoxia, encephalitis and temporal lobe epilepsy, among other conditions.