Anterograde amnesia

Hippocampus (brain)

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
Hippocampus (brain)

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Amnesie

Amnesia

Deficit in memory caused by brain damage or disease, but it can also be caused temporarily by the use of various sedatives and hypnotic drugs.

Deficit in memory caused by brain damage or disease, but it can also be caused temporarily by the use of various sedatives and hypnotic drugs.

Amnesie

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

Overview of the forms and functions of memory.

Retrograde amnesia

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.

Overview of the forms and functions of memory.

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

Transiente globale Amnesie MRT DWI axial

Transient global amnesia

Neurological disorder whose key defining characteristic is a temporary but almost total disruption of short-term memory with a range of problems accessing older memories.

Neurological disorder whose key defining characteristic is a temporary but almost total disruption of short-term memory with a range of problems accessing older memories.

Transiente globale Amnesie MRT DWI axial

Both TGA and anterograde amnesia deal with disruptions of short-term memory.

Midazolam

Benzodiazepine medication used for anesthesia, procedural sedation, trouble sleeping, and severe agitation.

Benzodiazepine medication used for anesthesia, procedural sedation, trouble sleeping, and severe agitation.

Injectable midazolam in 1 and 5 mg/ml strengths
Oklahoma State Penitentiary, the site of the state of Oklahoma's execution chamber

It works by inducing sleepiness, decreasing anxiety, and causing a loss of ability to create new memories.

0.5 mg tablets of the Ativan brand of lorazepam

Lorazepam

Benzodiazepine medication.

Benzodiazepine medication.

0.5 mg tablets of the Ativan brand of lorazepam
1987 advertisement. "In a world where certainties are few...no wonder Ativan is prescribed by so many caring clinicians."

It is also used during surgery to interfere with memory formation and to sedate those who are being mechanically ventilated.

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

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.

Structural formula of benzodiazepines.

Benzodiazepine

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.

Hippocampus (brain)

Blackout (drug-related amnesia)

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.

Hippocampus (brain)

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.

Molaison in 1953 before his surgery

Henry Molaison

American who had a bilateral medial temporal lobectomy to surgically resect the anterior two thirds of his hippocampi, parahippocampal cortices, entorhinal cortices, piriform cortices, and amygdalae in an attempt to cure his epilepsy.

American who had a bilateral medial temporal lobectomy to surgically resect the anterior two thirds of his hippocampi, parahippocampal cortices, entorhinal cortices, piriform cortices, and amygdalae in an attempt to cure his epilepsy.

Molaison in 1953 before his surgery
Most of Molaison's two hippocampi were removed bilaterally.

After the surgery, which was partially successful in controlling his seizures, Molaison developed severe anterograde amnesia: although his working memory and procedural memory were intact, he could not commit new events to his explicit memory.

Results of the 2010 ISCD study ranking the levels of damage caused by drugs, in the opinion of drug-harm experts. When harm to self and others is summed, alcohol was the most harmful of all drugs considered, scoring 72%.

Short-term effects of alcohol consumption

Results of the 2010 ISCD study ranking the levels of damage caused by drugs, in the opinion of drug-harm experts. When harm to self and others is summed, alcohol was the most harmful of all drugs considered, scoring 72%.
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The short-term effects of alcohol (more specifically ethanol) consumption range from a decrease in anxiety and motor skills and euphoria at lower doses to intoxication (drunkenness), stupor, unconsciousness, anterograde amnesia (memory "blackouts"), and central nervous system depression at higher doses.