• The hippocampus is the part of the brain that is involved in forming, organizing, and storing memories. It is a limbic system structure that is particularly important in forming new memories and connecting emotions and senses, such as smell and sound, to memories.
• The hippocampus is a horseshoe shaped structure, with an arching band of nerve fibers (fornix) connecting the hippocampal structures in the left and right brain hemispheres.
• The hippocampus is found in the brain's temporal lobes and acts as a memory indexer by sending memories out to the appropriate part of the cerebral hemisphere for long-term storage and retrieving them when necessary.

The hippocampus is the main structure of the hippocampal formation, which is composed of two gyri (brain folds) and the subiculum. The two gyri, the dentate gyrus and Ammon's horn (cornu ammonis), form interlocking connections with one another. The dentate gyrus is folded and nestled within the hippocampal sulcus (brain indentation).

Neurogenesis (new neuron formation) in the adult brain occurs in the dentate gyrus, which receives input from other brain areas and aids in new memory formation, learning, and spacial memory.