The hippocampus is part of the limbic system in the brain. It serves important roles in forming new memories, converting short-term to long-term memory and connecting events to emotional responses. This is one of the first regions of the brain to be damaged in Alzheimer’s patients, causing memory loss and confusion. Within the hippocampus, the cell types are layered. Here, you see a layer of neuronal nuclei in yellow, layered between nerve processes that are covered by a protective cellular coat of myelin basic protein (violet).