Īnother reference appeared with the term pes hippocampi, which may date back to Diemerbroeck in 1672, introducing a comparison with the shape of the folded back forelimbs and webbed feet of the mythological hippocampus, a sea monster with a horse's forequarters and a fish's tail. This has survived in abbreviated form as CA in naming the subfields of the hippocampus. "Ram's horn" was proposed by the Danish anatomist Jacob Winsløw in 1732 and a decade later his fellow Parisian, the surgeon de Garengeot, used "cornu Ammonis" – horn of (the ancient Egyptian god) Amun, who was often represented as having a ram's head. The German anatomist Duvernoy (1729), the first to illustrate the structure, also wavered between "seahorse" and "silkworm". 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 (1587), who likened it first to a silkworm and then to a seahorse ( Latin hippocampus, from Greek ἱππόκαμπος, from Greek ἵππος, "horse" + κάμπος, "sea monster"). Image 1: The human hippocampus and fornix (left) compared with a seahorse (right) 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. Many neurons in the rat and mouse hippocampus respond as place cells: that is, they fire bursts of action potentials when the animal passes through a specific part of its environment. In rodents as model organisms, the hippocampus has been studied extensively as part of a brain system responsible for spatial memory and navigation. LTP is widely believed to be one of the main neural mechanisms by which memories are stored in the brain. The form of neural plasticity known as long-term potentiation (LTP) was initially discovered to occur in the hippocampus and has often been studied in this structure. Since different neuronal cell types are neatly organized into layers in the hippocampus, it has frequently been used as a model system for studying neurophysiology. People with extensive, bilateral hippocampal damage may experience anterograde amnesia: the inability to form and retain new memories. Damage to the hippocampus can also result from oxygen starvation ( hypoxia), encephalitis, or medial temporal lobe epilepsy. In Alzheimer's disease (and other forms of dementia), the hippocampus is one of the first regions of the brain to suffer damage short-term memory loss and disorientation are included among the early symptoms. In humans, it contains two main interlocking parts: the hippocampus proper (also called Ammon's horn), and the dentate gyrus. The hippocampus, as the medial pallium, is a structure found in all vertebrates. The hippocampus is located in the allocortex, with neural projections into the neocortex in humans, as well as primates. The hippocampus is part of the limbic system, and plays important roles in the consolidation of information from short-term memory to long-term memory, and in spatial memory that enables navigation. Humans and other mammals have two hippocampi, one in each side of the brain. In addition to the memory function, the hippocampus subserves spatiotemporal orientation.The hippocampus (via Latin from Greek ἱππόκαμπος, ' seahorse') is a major component of the brain of humans and other vertebrates. The disruption of this circuit by decline of neurons of the entorhinal cortex is a hallmark of human Alzheimer’s disease which leads to a loss of the short-term and long-term memory. It is part of a functionally very important circuit for the short-term and long-term memory starting in the neighboring entorhinal cortex via the dentate gyrus and Cornu Ammonis back to the entorhinal cortex (classical trisynaptic pathway). 10), the hippocampus consists mainly of three layers and can roughly be subdivided into the dentate gyrus and the Cornu Ammonis. The human hippocampus has a basal position in the telencephalon but, regarding its fine structure, is very much alike that of the rodent hippocampus. The rodent hippocampus is a continuous structure that changes its cranial dorsal position to a lateroventral location in the more caudal parts where it eventually reaches the ventral surface of the brain. The hippocampus is the phylogenetically second oldest part of the telencephalon after the olfactory system (Chap.