Hippokampus

Hippokampus is a term used in various contexts, often as a variant spelling of hippocampus. In English, hippocampus typically refers to the brain structure, while the seahorse genus is written Hippocampus. The name derives from Greek hippos ("horse") and kampos ("sea monster"), reflecting its seahorse-inspired etymology.

In neuroscience, the hippocampus is a paired, seahorse-shaped structure in the medial temporal lobe. It is essential for forming and consolidating declarative memories and for spatial navigation and contextual processing. Subfields include CA1–CA3, the dentate gyrus, and the subiculum, with connections to the entorhinal cortex and other limbic regions. The hippocampus supports encoding, retrieval, and integration of experiences, and shows adult neurogenesis in the dentate gyrus. Degeneration can produce memory impairment, as seen in Alzheimer's disease.

In zoology, the genus Hippocampus comprises seahorses and related pipefishes. Species inhabit shallow tropical and temperate marine waters and are noted for male pregnancy, in which males carry eggs in a brood pouch until birth. Seahorses have elongated snouts, a prehensile tail, and bony armor-like plates. They face threats from habitat loss, bycatch, and the aquarium trade, with several species listed on the IUCN Red List at various risk levels.

Etymology and usage: while hippokampus can appear as an alternative transliteration, in standard modern English the brain region is hippocampus and the fish genus is Hippocampus. The terms share origin but refer to distinct biological concepts.