Hippocampus
hideThe hippocampus is a major component of the brains of humans and other mammals. It belongs to the limbic system and plays important roles in long-term memory and spatial navigation. Like the cerebral cortex, with which it is closely associated, it is a paired structure, with mirror-image halves in the left and right sides of the brain. In humans and other primates, the hippocampus is located inside the medial temporal lobe, beneath the cortical surface. Its curved shape reminded early anatomists of the horns of a ram (Cornu Ammonis), or a seahorse. The name, in fact, was taken by the sixteenth century anatomist Julius Caesar Aranzi from the Greek word for seahorse (Greek: ιππος, hippos = horse, καμπος, kampos = sea monster).
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 hippocampal damage may experience amnesia—the inability to form or retain new memories.
In rodents, the hippocampus has been studied extensively as part of the 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.
Because of its densely packed layers of neurons, the hippocampus 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.
For more information about Hippocampus, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with hippocampus
Rodent smoke screen
Medicine & Health / Psychology & Psychiatry
7 hours ago |
not rated yet |
0
Rats passively exposed to tobacco smoke become dependent on nicotine, according to a new study by Dr. Adrie Bruijnzeel and colleagues from the University of Florida in the US. Their findings of how rats' brains respond to ...
Don't I know you? Research sheds light on memorial retrieval
Medicine & Health / Neuroscience
Dec 07, 2009 |
not rated yet |
0
We have all had the embarrassing experience of seeing an acquaintance in an unfamiliar setting. We know we know them but can't recall who they are. But with the correct cues from conversation or context, something seems ...
Acute stress leaves epigenetic marks on the hippocampus
Medicine & Health / Psychology & Psychiatry
Nov 24, 2009 |
4.7 / 5 (9) |
0
(PhysOrg.com) -- Scientists are learning that the dynamic regulation of genes -- as much as the genes themselves -- shapes the fate of organisms. Now the discovery of a new epigenetic mechanism regulating genes in the brain ...
New discovery about the formation of new brain cells
Nov 23, 2009 |
5 / 5 (2) |
0
The generation of new nerve cells in the brain is regulated by a peptide known as C3a, which directly affects the stem cells' maturation into nerve cells and is also important for the migration of new nerve cells through ...
To make memories, new neurons must erase older ones
Nov 12, 2009 |
4.4 / 5 (8) |
0
Short-term memory may depend in a surprising way on the ability of newly formed neurons to erase older connections. That's the conclusion of a report in the November 13th issue of the journal Cell that provid ...
An end to sleep problems? Researchers discover enzyme behind effects of sleep deprivation
Nov 26, 2009 |
4 / 5 (1) |
0
There is hope for those who miss one night too many or whose children keep them up at night. The unwelcome effects of a bad night's sleep - forgetfulness, impaired mental performance - can be dealt with by reducing the concentration ...
Theory about long and short-term memory questioned
Medicine & Health / Neuroscience
Nov 09, 2009 |
4.7 / 5 (6) |
0
The long-held theory that our brains use different mechanisms for forming long-term and short-term memories has been challenged by new research from UCL, published today in PNAS.
Unravelling the pathology of dementia
Nov 10, 2009 |
not rated yet |
0
Combination therapies to tackle multiple changes in the brain may be needed to combat the growing problem of dementia in ageing societies, according to a study published this week in the open access journal PLoS Medicine. The st ...
