Hippocampus (brain)
Amnesie

In neurology, anterograde amnesia is a loss of the ability to create new memories after the event that caused amnesia, leading to a partial or complete inability to recall the recent past, while long-term memories from before the event remain intact.

- Anterograde amnesia

This is in contrast to retrograde amnesia, where memories created prior to the event are lost while new memories can still be created.

- Anterograde amnesia

There are two main types of amnesia: retrograde amnesia and anterograde amnesia.

- Amnesia

This would resemble generic amnesia.

- Retrograde amnesia

Anterograde amnesia is a similar condition that deals with the inability to form new memories following the onset of an injury or disease.

- Retrograde amnesia
Hippocampus (brain)

3 related topics with Alpha

Overall

Humans have two hippocampi, one in each hemisphere of the brain. They are located in the medial temporal lobes of the cerebrum. In this lateral view of the human brain, the frontal lobe is at the left, the occipital lobe at the right, and the temporal and parietal lobes have largely been removed to reveal one of the hippocampi underneath.

Hippocampus

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Major component of the brain of humans and other vertebrates.

Major component of the brain of humans and other vertebrates.

Humans have two hippocampi, one in each hemisphere of the brain. They are located in the medial temporal lobes of the cerebrum. In this lateral view of the human brain, the frontal lobe is at the left, the occipital lobe at the right, and the temporal and parietal lobes have largely been removed to reveal one of the hippocampi underneath.
Image 1: The human hippocampus and fornix (left) compared with a seahorse (right)
Image 2: Cross-section of cerebral hemisphere showing structure and location of hippocampus
Image 3: Coronal section of the brain of a macaque monkey, showing hippocampus (circled)
Image 4: Basic circuit of the hippocampus, as drawn by Cajal DG: dentate gyrus. Sub: subiculum. EC: entorhinal cortex
Image 5: Hippocampal location and regions
Rats and cognitive maps
Image 6: Spatial firing patterns of 8 place cells recorded from the CA1 layer of a rat. The rat ran back and forth along an elevated track, stopping at each end to eat a small food reward. Dots indicate positions where action potentials were recorded, with color indicating which neuron emitted that action potential.
Image 7: Examples of rat hippocampal EEG and CA1 neural activity in the theta (awake/behaving) and LIA (slow-wave sleep) modes. Each plot shows 20 seconds of data, with a hippocampal EEG trace at the top, spike rasters from 40 simultaneously recorded CA1 pyramidal cells in the middle (each raster line represents a different cell), and a plot of running speed at the bottom. The top plot represents a time period during which the rat was actively searching for scattered food pellets. For the bottom plot the rat was asleep.
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Image 9: An EEG showing epilepsy right-hippocampal seizure onset
Image 10: An EEG showing epilepsy left-hippocampal seizure onset
Image 11: Drawing by Italian pathologist Camillo Golgi of a hippocampus stained using the silver nitrate method
thumb|Hippocampus highlighted in green on coronal T1 MRI images
thumb|Hippocampus highlighted in green on sagittal T1 MRI images
thumb|Hippocampus highlighted in green on transversal T1 MRI images

People with extensive, bilateral hippocampal damage may experience anterograde amnesia: the inability to form and retain new memories.

It is apparent that complete amnesia occurs only when both the hippocampus and the parahippocampus are damaged.

The unexpected outcome of the surgery was severe anterograde and partial retrograde amnesia; Molaison was unable to form new episodic memories after his surgery and could not remember any events that occurred just before his surgery, but he did retain memories of events that occurred many years earlier extending back into his childhood.

Long-term memory

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Stage of the Atkinson–Shiffrin memory model in which informative knowledge is held indefinitely.

Stage of the Atkinson–Shiffrin memory model in which informative knowledge is held indefinitely.

Research by Meulemans and Van der Linden (2003) found that amnesiac patients with damage to the medial temporal lobe performed more poorly on explicit learning tests than did healthy controls.

His subsequent total anterograde amnesia and partial retrograde amnesia provided the first evidence for the localization of memory function, and further clarified the differences between declarative and procedural memory.

Thiamine

Korsakoff syndrome

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Thiamine

Korsakoff syndrome (KS) is a disorder of the central nervous system characterized by amnesia, deficits in explicit memory, and confabulation.

1) anterograde amnesia, memory loss for events after the onset of the syndrome

2) retrograde amnesia, memory loss extends back for some time before the onset of the syndrome