Region of the brain involved in regulating multiple cognitive and emotional processes.
It is sensitive to moderate and severe traumatic brain injury.
Is vulnerable to mild traumatic brain injury, as indicated by volume reduction, and postconcussion disruption of hippocampal function and connectivity.
A hippocampus is located in the medial temporal lobe of the brain. under the cerebral cortex.
There are two hippocampi, one in each side of the brain.
Part of the limbic system and helps in the consolidation of information from short-term memory to long-term memory.
Declarative memory, which are those memories which can be consciously recalled is formed in the area of the hippocampus called the dentate gyrus.
Helps in spatial navigation.
It contains two main interlocking parts: Ammon’s horn and the dentate gyrus.
It is is one of the first regions of the brain to suffer damage in Alzheimer’s disease, impairing memory loss and causing disorientation.
Damage to the hippocampus can also result from hypoxia, encephalitis, or medial temporal lobe epilepsy.
Patients with bilateral hippocampal damage may experience anterograde amnesia.
A form of neural plasticity known as long-term potentiation (LTP) occurs in the hippocampus and is one of the main mechanisms by which memory is stored in the brain.
Hippocampal volume decreases with decreasing plasma levels of BDNF.
Spatial coding plays an important role in hippocampal function.
Plays an important role in the formation of new memories about experienced events.
The amygdala and hippocampus create and encode the memory and emotion due to pain stimuli.
Due to its bilateral nature damage to the hippocampus occurring in only one hemisphere allows the brain to retain near-normal memory functioning.
Damage to the hippocampi in both hemispheres results in difficulties in forming new memories, and often also affects memories formed before the damage occurred.
Hippocampal damage does not affects ability to learn new skills.
Hippocampus plays a role in finding shortcuts and new routes between familiar places.
The hippocampus is at the edge of the cerebral cortex and is part of the limbic system.
The limbic system includes the hippocampus, cingulate cortex, olfactory cortex, and amygdala and comprise the neural basis of emotion.
The hippocampus as a whole has the shape of a curved tube, which has been variously compared to a seahorse, a ram’s horn or a banana.
The entorhinal cortex (EC) located in the parahippocampal gyrus, is part of the hippocampal region.
The entorhinal cortex (EC) is connected with many other parts of the cerebral cortex, the medial septal nucleus, the anterior nuclear complex and nucleus reuniens of the thalamus and the supramammillary nucleus of the hypothalamus, the raphe nuclei and locus coeruleus in the brainstem.
Receives modulatory input from the serotonin, norepinephrine, and dopamine systems, and from nucleus reuniens of the thalamus.
The medial septal area sends cholinergic and GABAergic fibers to all parts of the hippocampus and plays a key role in controlling the physiological state of the hippocampus.
Damage to the septal area abolishes the hippocampal theta rhythm and impairs certain types of memory.
The cortical region adjacent to the hippocampus is known as the parahippocampal gyrus and includes the entorhinal cortex and also the perirhinal cortex.
The perirhinal cortex plays an important role in visual recognition of complex objects and contributes to memory function.
Complete amnesia occurs only when both the hippocampus and the parahippocampus are damaged.
The dorsal region of the hippocampus provides spatial and verbal memory, and for the learning of conceptual information.
The intermediate hippocampus has overlapping characteristics of both the ventral and dorsal hippocampus.
The ventral hippocampus functions in fear responses and affective processes.
The hippocampus shows two major modes of EEG activity: theta and large irregular activity.
The theta mode hippocampal activity appears during states of active, alert behavior, especially locomotion, and also during REM sleep.
Theta EEG activity demonstrates large regular waves with a frequency range of 6 to 9 Hertz, and the main groups of hippocampal neurons are silent, while the small remaining fraction fire at relatively high rates, up to 50 spikes in one second.
Because of its densely packed neural layers the hippocampus generates some of the largest EEG signals of any brain structure.
Proposed that memories are stored within the hippocampus during behavior and then later transferred to the neocortex during sleep.
Hippocampal disruption is one of the earliest signs of age-related conditions such as Alzheimer’s disease, but even normal aging is associated with a gradual decline in some types of memory.
Hippocampus is thought to play a central role in memory.
The hippocampus contains high levels of glucocorticoid receptors, making it vulnerable to long-term stress.
Hippocampus is one of very few brain regions where new neurons continue to be created throughout life.
Stress-related steroid production affects the hippocampus by reducing the excitability of some neurons, inhibits the genesis of new neurons in the dentate gyrus, and by causes atrophy of dendrites in pyramidal cells of the CA3 region.
Exposure to long-lasting traumatic stress results in atrophy of the hippocampus more than of other parts of the brain, and is found in post-traumatic stress disorder,schizophrenia and, Cushing’s disease and severe depression.
The hippocampus is often the focus of epileptic seizures, and fibrosis is the most commonly visible type of tissue damage in temporal lobe epilepsy.
Epilepsy may be caused by hippocampal abnormalities or the hippocampus may be damaged by cumulative effects of seizures.
Many case reports have found reductions in the size of the hippocampus in schizophrenic subjects, probably the result from altered development.
Transient global amnesia may be due to venous congestion of the brain, leading to ischemia of the hippocampus involved in memory.