|Jmol-3D images||Image 1|
|Molar mass||114.10 g mol−1|
184-185 °C, 457-458 K, 363-365 °F
|Solubility in water||very soluble|
|Solubility in ethanol||slightly soluble|
|Solubility in methanol||very soluble|
| (what is: / ?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Muscimol (agarin, pantherine) is the major psychoactive alkaloid present in many mushrooms of the Amanita genus. Muscimol is a potent, selective agonist for the GABAA receptors and displays sedative-hypnotic and dissociative psychoactive effects.
Muscimol is the psychoactive compound responsible for the effects of Amanita muscaria intoxication. Ibotenic acid, a neurotoxic secondary metabolite of Amanita muscaria, serves as a prodrug to muscimol when the mushroom is ingested or dried, converting to muscimol via decarboxylation.
Muscimol is produced naturally in the mushrooms Amanita muscaria and Amanita pantherina, along with muscarine, muscazone, and ibotenic acid. A. muscaria and A. pantherina should be eaten with caution and prepared properly to lessen effects of nausea; no official deaths from poisoning have been recorded from A. muscaria and A. pantherina. In A. muscaria, the layer just below the skin of the cap contains the highest amount of muscimol, and is therefore the most psychoactive portion.
Muscimol is a potent GABAA agonist, activating the receptor for the brain's major inhibitory neurotransmitter, GABA. Muscimol actually binds to the same site on the GABAA receptor complex as GABA itself, as opposed to other GABAergic drugs such as barbiturates and benzodiazepines which bind to separate regulatory sites. GABAA receptors are widely distributed in the brain, and so when muscimol is administered, it alters neuronal activity in multiple regions including the cerebral cortex, hippocampus, and cerebellum.
While muscimol is conventionally thought of as a selective GABAA agonist, it is also a potent partial agonist at the GABAA-rho receptor, and so its range of effects results from a combined action at both targets.
During a test involving rabbits connected to an EEG, muscimol showed a distinctly synchronized EEG tracing. This is substantially different from serotonergic psychedelics, as brainwave patterns will generally show a desynchronization. In higher doses (2 mg/kg), the EEG will show characteristic spikes.
If consumed, muscimol will pass through the human body, and be excreted unchanged in the subject's urine.
The psychoactive dose of muscimol is around 10–15 mg for a normal person. A Guide to British Psilocybin Mushrooms by Richard Cooper published in 1977 recommends a smaller dose, 8.5 mg, and suggests that it is possible for this amount to be present in as little as 1 g of dried A. muscaria. A correct dose may be difficult to determine because potency varies dramatically from one mushroom to the next.
Many of muscimol's effects are consistent with its pharmacology as a GABAA receptor agonist, presenting many depressant or sedative-hypnotic effects, similar to ethanol. Unlike ethanol however, muscimol can present sensory and psychological effects somewhat reminiscent of a psychedelic drug, including dissociation, synesthesia, auditory and visual distortions and hallucinations, altered thought processes, and perhaps most notably micropsia and or macropsia, as these effects may have provided the inspiration for the effect of Alice eating the mushroom (changing size) in Lewis Carroll's Alice's Adventures in Wonderland. The mushrooms that bear muscimol have also been reported to induce lucid dreaming when an individual falls asleep under its influence. Many of muscimol's hallucinogenic effects would not be regarded as psychedelic in the traditional sense though and bear the strongest resemblance to the hallucinatory effects of similarly-acting drugs like zolpidem, the symptoms of delirium tremens or benzodiazepine withdrawal syndrome, and hypnagogic hallucinations, albeit without and even in contrast to the associated negative effects of anxiety, psychosis or a general state of fear and depression.  Jonathan Ott describes the effects of Amanita pantherina below:
|“||About 90 minutes after ingestion ... I noticed that I was experiencing changes in visual perception. These effects became stronger over the next hour or some, and were characterized by sensing an 'alive quality' in inanimate objects, wavy motion in the visual field like a Van Gogh canvas ... and mild distortion of size, distance and depth perception. Auditory hallucination were also prominent -- especially the effect, called 'anahata sounds' of yoga, of hearing fine high-pitched sounds like bells and violin strings.||”|
See also 
- Psychedelic drug
- Psychoactive drug
- Amanita muscaria
- Amanita pantherina
- Ibotenic acid
- List of entheogens
- The Merck Index, 12th Edition
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- Erowid Psychoactive Amanitas Vault : Chemistry
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