- Hippocampus
- An area buried deep in the forebrain that helps regulate emotion and memory.
* * *The complex, internally convoluted structure that forms the medial margin (“hem”) of the cortical mantle of the cerebral hemisphere, bordering the choroid fissure of the lateral ventricle, and composed of two gyri (Ammon horn and the dentate gyrus), together with their white matter, the alveus and fimbria hippocampi. In monkeys, apes, and humans the h. is confined to the temporal lobe by the massive development of the corpus callosum. Cytoarchitecturally a unique form of allocortex (archicortex), the h. forms part of the limbic system (formerly rhinencephalon). Its major afferent connections are with the entorhinal area of the parahippocampal gyrus, and transparent septum; by way of the fornix it projects to the septum, anterior nucleus of the thalamus, and mamillary body. SYN: h. major, major h.. [G. hippocampos, seahorse]
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hip·po·cam·pus .hip-ə-'kam-pəs n, pl -pi -.pī, -(.)pē a curved elongated ridge that is an important part of the limbic system, extends over the floor of the descending horn of each lateral ventricle of the brain, consists of gray matter covered on the ventricular surface with white matter, and is involved in forming, storing, and processing memory see pes hippocampi* * *
n.a swelling in the floor of the lateral ventricle of the brain. It contains complex foldings of cortical tissue and is involved, with other connections of the hippocampal formation, in the workings of the limbic system.• hippocampal adj.* * *
hip·po·cam·pus (hip″o-kamґpəs) [Gr. hippokampos sea horse] [TA] a convoluted elevation of gray matter extending the entire length of the floor of the temporal horn of the lateral ventricle; it is part of the limbic system and plays major roles in short term memory and spatial navigation. Official anatomical terminology and many authorities use the term to denote the entire structure including the hippocampus proper, the dentate gyrus, and the subicular complex (presubiculum, parasubiculum, and subiculum), but it can also be used more restrictively, most often denoting the hippocampus proper, in which case the entire structure may be called the hippocampal formation. hippocampal adj
Hippocampus in a dissection of the right lateral ventricle.
Schematic diagram of the hippocampal formation showing the disposition of the various cell fields. CA1–4 denotes a classification scheme for subdividing the cornu region into a series of radially disposed fields.
Medical dictionary. 2011.
