CA3 Field of the Cornu Ammonis

**Semantic type:** Anatomical Structure

**Definition:** The third of four regions in the cornu ammonis of the hippocampus which receives inputs from mossy fibers originating from the granule cells in the dentate gyrus and from inputs along the perforant path originating in layers II and III within the entorhinal cortex. This area contains pyramidal cells that send axons to the CA1 field and acts as a pacemaker, setting the pace for neuronal firing in the hippocampus.