Hippocampus

The hippocampus is a major component of the brains of humans and other vertebrates. It belongs to the limbic system and plays important roles in the consolidation of information from short-term memory to long-term memory and spatial navigation. Humans and other mammals have two hippocampi, one in each side of the brain. The hippocampus is a part of the cerebral cortex, and in primates is located in the medial temporal lobe, underneath the cortical surface. It contains two main interlocking parts: Ammon's horn and the dentate gyrus.

In Alzheimer's disease, the hippocampus is one of the first regions of the brain to suffer damage; memory problems and disorientation appear among the first 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 or retain new memories.

In rodents, the hippocampus has been studied extensively as part of a brain system responsible for spatial memory and navigation. 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. Hippocampal place cells interact extensively with head direction cells, whose activity acts as an inertial compass, and with grid cells in the neighboring entorhinal cortex.

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 first 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 memory is stored in the brain.

Read more about Hippocampus:  Name, Functions, Anatomy, Hippocampal Formation, Physiology, Evolution

Other articles related to "hippocampus":

Hippocampus Anatomy
... Hippocampus anatomy describes the physical aspects and properties of the hippocampus, a neural structure in the medial temporal lobe of the brain that has a distinctive, curved shape that has been ... In primate brains, including humans, the portion of the hippocampus near the base of the temporal lobe is much broader than the part at the top ... of the hole collectively make up the so-called limbic system (Latin limbus = border), with the hippocampus lining the posterior edge of this hole ...
Amygdalohippocampectomy - Procedure
... seizures can be anatomically localized to the hippocampus and amygdala ... amygdalohippocampectomy will remove only the offending portions of the hippocampus and amygdala ... origin of seizure activity, the removal of the hippocampus and amygdala is usually indicated ...
Synaptic Noise - In The Hippocampus
... noise has become clear through ongoing research of the brain, specifically the hippocampus ... The hippocampus is a region of the forebrain in the medial temporal lobe closely associated with memory formation and recollection ... of synaptic noise in the signal functions within the hippocampus, and therefore in memories, whether solidifying or interfering ...
Hippocampus - Evolution
... The hippocampus has a generally similar appearance across the range of mammal species, from monotremes such as the echidna to primates such as humans ... Therefore, the hippocampus takes up a much larger fraction of the cortical mantle in rodents than in primates ... In adult humans, the volume of the hippocampus on each side of the brain is about 3–3.5 cm3, as compared to 320–420 cm3 for the volume of the neocortex ...
Lynn Nadel
... Nadel specializes in memory, and has investigated the role of the hippocampus in memory formation ... with John O'Keefe, he coauthored the influential 1978 book The Hippocampus as a Cognitive Map, which defended the theory that the hippocampus learns and ... He later advanced Multiple trace theory, which posits that the hippocampus is always involved in storage and retrieval of episodic memory, but semantic memory can be ...