Hippocampus

Hippocampus

The hippocampus is a major component of the brain of humans and other vertebrates. It is part of the limbic system, and plays important roles in the consolidation of information. In Alzheimer’s disease, the hippocampus is one of the first regions to suffer damage. People with extensive, bilateral hippocampal damage may experience anterograde amnesia.

About Hippocampus in brief

Summary HippocampusThe hippocampus is a major component of the brain of humans and other vertebrates. The hippocampus is part of the limbic system, and plays important roles in the consolidation of information. It is located under the cerebral cortex in the allocortex, and in primates it is in the medial temporal lobe. It contains two main interlocking parts: the hippocampus proper and the dentate gyrus. In Alzheimer’s disease, the hippocampus is one of the first regions to suffer damage. People with extensive, bilateral hippocampal damage may experience anterograde amnesia: the inability to form and retain new memories. The form of neural plasticity known as long-term potentiation was initially discovered to occur in the hippocampus and has often been studied in this structure. Hippocampal place cells interact extensively with head direction cells, whose activity acts as an inertial compass, and conjecturally with grid cells in the neighboring entorhinal cortex. The earliest description of the ridge running along the floor of the temporal horn of the lateral ventricle comes from the Venetian anatomist Julius Caesar Aranzi, who likened it first to a silkworm and then to a seahorse. The renaming of the hippocampus as hippocampus major, and the calcar avis as hippocampus minor, has been attributed to Félix Vicq-d’Azyr systematising nomenclature of parts of thebrain in 1786. In 1861 the hippocampus minor became the centre of a dispute over human evolution between Thomas Henry Huxley and Richard Owen, satirised as the Great Hippocampus Question.

The term hippocampus minor fell from use in anatomy textbooks, and was officially removed in the Nomina Anatomica of 1895. Today, the structure is just called the hippocampus, with the term Cornu Ammonis surviving in the names of the hippocampal subfields CA1-CA4. It can be seen as a ridge of gray matter, elevating from each lateral venticle into the medial lobe. This can be also seen as an inward fold of the inferior or temporal horn, which is also known as the inferior temporal horn. This ridge can also be seen in the anterior mammillary body, the anterior complex in the thalamus, the mammillium, the hypothalamic body and the mammilium. This is generally accepted to be the part that is involved with emotional behavior—the septum, the amygdala, the olfactory cortex, the cingulate cortex and the hippocampus. It was introduced in 1952 by Paul MacLean to describe the set of structures that line the edge of the cortex. These include the hippocampus,. cingulates cortex, olfaction cortex, and amygdala. It has been suggested that the hippocampus comprises the neural basis of emotion and comprise the anatomically connected parts of brain that are involved with emotion. The name hippocampus is also used to refer to the region of the body that is responsible for emotions such as fear and anger.