Hippocampus | |
---|---|
Details | |
Part of | Temporal lobe |
Identifiers | |
Latin | hippocampus |
MeSH | D006624 |
NeuroNames | 3157 |
NeuroLex ID | birnlex_721 |
TA98 | A14.1.09.321 |
TA2 | 5518 |
FMA | 275020 |
Anatomical terms of neuroanatomy |
The hippocampus (pl.: hippocampi; via Latin from Greek ἱππόκαμπος, 'seahorse'), also hippocampus proper, is a major component of the brain of humans and many other vertebrates. In the human brain the hippocampus, the dentate gyrus, and the subiculum are the components of the hippocampal formation located in the limbic system. The hippocampus plays important roles in the consolidation of information from short-term memory to long-term memory, and in spatial memory that enables navigation. In humans, and other primates the hippocampus is located in the archicortex, one of the three regions of allocortex, in each hemisphere with neural projections to the neocortex.[1][2][3][4] The hippocampus, as the medial pallium, is a structure found in all vertebrates.[5]
In Alzheimer's disease (and other forms of dementia), the hippocampus is one of the first regions of the brain to suffer damage;[6] short-term memory loss and disorientation are included among the early symptoms. Damage to the hippocampus can also result from oxygen starvation (hypoxia), encephalitis, or medial temporal lobe epilepsy. People with extensive, bilateral hippocampal damage may experience anterograde amnesia: the inability to form and retain new memories.
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. 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. LTP is widely believed to be one of the main neural mechanisms by which memories are stored in the brain.
In rodents as model organisms, the hippocampus has been studied extensively as part of a brain system responsible for spatial memory and navigation.[7] Many neurons in the rat and mouse hippocampi respond as place cells: that is, they fire bursts of action potentials when the animal passes through a specific part of its environment.[7] 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.[8]
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