part of hippocampus A curved elongated ridge that extends over the floor of the descending horn of each lateral ventricle of the brain and consists of gray matter covered on the ventricular surface with white matter; The hippocampus is a part of the temporal lobe, which has a well established role in learning, memory and emotion. BTO:0000601 BrendaTissueOBO hippocampus major major hippocampus limbic system temporal lobe