A report on Amnesia and Anterograde amnesia

Amnesie
Hippocampus (brain)

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

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

- Amnesia
Amnesie

9 related topics with Alpha

Overall

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.

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.

Retrograde amnesia

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Loss of memory-access to events that occurred or information that was learned in the past.

Loss of memory-access to events that occurred or information that was learned in the past.

This would resemble generic amnesia.

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

Lobes of the human brain (temporal lobe is shown in green)

Temporal lobe

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One of the four major lobes of the cerebral cortex in the brain of mammals.

One of the four major lobes of the cerebral cortex in the brain of mammals.

Lobes of the human brain (temporal lobe is shown in green)
Animation showing the position of the human left temporal lobe

The medial temporal lobes include the hippocampi, which are essential for memory storage, therefore damage to this area can result in impairment in new memory formation leading to permanent or temporary anterograde amnesia.

Amnesia, Korsakoff syndrome, Klüver–Bucy syndrome

Episodic memory

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Memory of everyday events that can be explicitly stated or conjured.

Memory of everyday events that can be explicitly stated or conjured.

For example, anterograde amnesia, from damage of the medial temporal lobe, is an impairment of declarative memory that affects both episodic and semantic memory operations.

The label "amnesia" is most often given to patients with deficits in episodic memory.

Short-term memory

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Capacity for holding a small amount of information in an active, readily available state for a short interval.

Capacity for holding a small amount of information in an active, readily available state for a short interval.

One form of evidence cited in favor of the existence of a short-term store comes from anterograde amnesia, the inability to learn new facts and episodes.

Patients with this form of amnesia have an intact ability to retain small amounts of information over short time scales (up to 30 seconds) but have little ability to form longer-term memories (illustrated by patient HM).

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

Blackout (drug-related amnesia)

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Phenomenon caused by the intake of any substance or medication in which short-term and long-term memory creation is impaired, therefore causing a complete inability to recall the past.

Phenomenon caused by the intake of any substance or medication in which short-term and long-term memory creation is impaired, therefore causing a complete inability to recall the past.

Blackouts are frequently described as having effects similar to that of anterograde amnesia, in which the subject cannot recall any events after the event that caused amnesia.

Structural formula of benzodiazepines.

Benzodiazepine

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Fusion of a benzene ring and a diazepine ring.

Fusion of a benzene ring and a diazepine ring.

Structural formula of benzodiazepines.
Midazolam 1 & 5 mg/mL injections (Canada)
Temazepam (Normison) 10 mg tablets
Addiction experts in psychiatry, chemistry, pharmacology, forensic science, epidemiology, and the police and legal services engaged in delphic analysis regarding 20 popular recreational drugs. Benzodiazepines were ranked in this graph 7th in dependence, physical harm, and social harm.
Diazepam 2 mg and 5 mg diazepam tablets, which are commonly used in the treatment of benzodiazepine withdrawal.
Chlordiazepoxide 5 mg capsules, which are sometimes used as an alternative to diazepam for benzodiazepine withdrawal. Like diazepam it has a long elimination half-life and long-acting active metabolites.
Schematic diagram of the (α1)2(β2)2(γ2) GABAA receptor complex that depicts the five-protein subunits that form the receptor, the chloride (Cl−) ion channel pore at the center, the two GABA active binding sites at the α1 and β2 interfaces and the benzodiazepine (BZD) allosteric binding site at the α1 and γ2 interface.
Left: The 1,4-benzodiazepine ring system. Right: 5-phenyl-1H-benzo[e] [1,4]diazepin-2(3H)-one forms the skeleton of many of the most common benzodiazepine pharmaceuticals, such as diazepam (7-chloro-1-methyl substituted).
A pharmacophore model of the benzodiazepine binding site on the GABAA receptor. White sticks represent the carbon atoms of the benzodiazepine diazepam, while green represents carbon atoms of the nonbenzodiazepine CGS-9896. Red and blue sticks are oxygen and nitrogen atoms that are present in both structures. The red spheres labeled H1 and H2/A3 are, respectively, hydrogen bond donating and accepting sites in the receptor, while L1, L2, and L3 denote lipophilic binding sites.
The molecular structure of chlordiazepoxide, the first benzodiazepine. It was marketed by Hoffmann–La Roche from 1960 branded as Librium.
Xanax (alprazolam) 2 mg tri-score tablets

High doses of many shorter-acting benzodiazepines may also cause anterograde amnesia and dissociation.

Benzodiazepines are effective as medication given a couple of hours before surgery to relieve anxiety. They also produce amnesia, which can be useful, as patients may not remember unpleasantness from the procedure. They are also used in patients with dental phobia as well as some ophthalmic procedures like refractive surgery; although such use is controversial and only recommended for those who are very anxious. Midazolam is the most commonly prescribed for this use because of its strong sedative actions and fast recovery time, as well as its water solubility, which reduces pain upon injection. Diazepam and lorazepam are sometimes used. Lorazepam has particularly marked amnesic properties that may make it more effective when amnesia is the desired effect.