Cornu ammonis



Cornu ammonis, literally "Amun's horns", is another name for the hippocampus. Abbreviated as CA, the term is also used to refer to the different hippocampal subfields, including CA1, CA2, and CA3. For example, input comes into the hippocampus from the entorhinal cortex to the dentate gyrus. The dentate gyrus then sends information to the next relay within the hippocampus, CA3.

Cut in cross section, the hippocampus is a C-shaped structure that resembles a ram's horns. The name cornu ammonis refers to the Egyptian deity Amun, who has the head of a ram. The horned appearance of the hippocampus is caused by cell density differentials and the existence of varying degrees of neuronal fibers.