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Fungi and Water
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
In addition, some species of amanita genus like Amanita pantherina and A. muscaria have hallucinogenic effects (96). They contain two constituents called ibotenic acid and muscimol which are responsible for the hallucinogenic effects. Ibotenic acid is a powerful agonist of N-methyl-D-aspartic-acid receptor and muscimol is a potent gamma-aminobutyric acid A agonist (96). The intoxications caused by A. muscaria were long believed to be due to muscarine, but it was demonstrated that muscarine is present in small amounts. People around the world have intentionally eaten A. muscaria or A. pantherina to evoke euphoria and hallucinations (96). The most common symptoms of intoxication are dizziness, drowsiness, motor depression, ataxia, changes in mood, gastrointestinal disturbances, and muscle twitches (96). Fatality due to Amanita pantherina and A. muscaria poisoning is rare. In most cases recovery is complete after 24 hours. The treatment is mainly symptomatic. Cholinesterase inhibitors, benzodiazepines, or phenobarbitone can be used in case of seizures (96).
Diseases of the Nervous System
Published in George Feuer, Felix A. de la Iglesia, Molecular Biochemistry of Human Disease, 2020
George Feuer, Felix A. de la Iglesia
Mushroom poisoning or mycetism is connected with widely varying classes of neurotoxins.364 These include Amanita muscaria, which produces ibotenic acid, muscimol and muscazone, and Inocybes and Clitocybes mushrooms, which produce muscarine. Amanita phalloides is the most toxic mushroom; they synthesize amatoxins: cyclic octapeptides and phallotoxins:cyclic heptapeptides.90,165,268 The principal amatoxin is amanitin, and the most important phallotoxin is phalloidin. The action of various mushroom toxins resides in the effects on several nerve functions such as GABA-like action inhibiting central neurons, inhibition of RNA polymease II, depletion of nuclear RNA preventing protein synthesis, and disruption or dissolution of cell membranes and membranes of lysosomes, endoplasmic reticulum, and Golgi bodies.176,231,268
The Circuitry Mediating the Translation of Motivational Stimuli Into Adaptive Motor Responses
Published in Peter W. Kalivas, Charles D. Barnes, Limbic Motor Circuits and Neuropsychiatry, 2019
Peter W. Kalivas, Lynn Churchill, Mark A. Klitenick
Compared to the VTA and nucleus accumbens, the pharmacology of the VP is less well characterized. Table 1 reveals that motor activity can be elicited pharmacologically from the VP by the stimulation of mu opioid,91,92 DA,24 EAA73 and tachykinin receptors (unpublished personal observation) or inhibition of GABAA receptors.92 The stimulation of GABAA receptors produces a biphasic effect with respect to dose. Thus, at low doses muscimol inhibits motor activity elicited pharmacologically from the nucleus accumbens while at higher doses it increases locomotion.91,92 The microinjection of neurotensin into the VP was found to partly inhibit motor activity elicited by the administration of opioids or DA into the nucleus accumbens.76
The White Panther – Rare exposure to Amanita multisquamosa causing clinically significant toxicity
Published in Clinical Toxicology, 2021
V. Vohra, I. V. Hull, K. T. Hodge
Scant literature exists surrounding Amanita multisquamosa exposures. Toxicity has been compared to Amanita muscaria ingestion, with primarily neurological features and mild gastrointestinal (GI) effects [2,3]. Previous cases include a Canadian family who experienced GI symptoms and demonstrated erratic behavior three hours after eating cooked specimens, resembling Amanita muscaria toxicosis [3]. High concentrations of ibotenic acid and muscimol have been found in Amanita multisquamosa samples, supporting comparisons to Amanita muscaria [4]. Ibotenic acid exerts excitatory central nervous system (CNS) effects while muscimol produces CNS depression [5]. Symptoms may appear within 30–120 min and can last 10–24 h [4,5]. Symptomatic and supportive care is indicated [5]. Our patient had a cardiac conduction abnormality of unknown etiology. Comprehensive molecular characterization of other toxins in Amanita multisquamosa has not been elucidated, therefore this exposure cannot be ruled out as a potential cause.
Ultrastructural GABA immunogold labeling in the substantia nigra pars reticulata of kindled genetic absence epilepsy rats
Published in Ultrastructural Pathology, 2020
Serap Sirvanci, Dilek Akakin, Medine Gulcebi İdrizoglu, Ozlem Tugce Kaya, Tugba Karamahmutoglu, Zehra Nur Turgan Aşık, Filiz Onat
The substantia nigra (SN) is a part of the midbrain and has two regions: Pars compacta (SNC) and pars reticulata (SNR).11,12 The SNR is larger and contains anterior (SNRa) and posterior (SNRp) parts.13,14 Several studies reported the role of SNR in regulating convulsive and nonconvulsive epileptic seizures.14–16 GABAergic neurons are the main cell types of the SNR, which is also targeted by GABAergic inputs from the striatonigral pathway.11,12,14 An increase in the activity of this pathway or exogenous application of GABA or GABA agonists such as muscimol causes increased GABAergic transmission in the SNR, resulting in decreased firing rate of GABAergic neurons in the SNR.12,14,17,18 These conditions lead to disinhibition of the output structures of the SNR, such as the superior colliculus and the ventromedial thalamus.14 Decreasing the activity of the SNR results in the suppression of seizures.12,14
Toxicity of muscimol and ibotenic acid containing mushrooms reported to a regional poison control center from 2002–2016
Published in Clinical Toxicology, 2019
Michael J. Moss, Robert G. Hendrickson
There are several Amanita mushroom species throughout the world which contain ibotenic acid and muscimol including Amanita. Muscaria (AM), A. pantherina (AP), A. gemmata, A. aprica, and A. regalis [1–3]. AM has been used by various cultures for religious activities, supporting work and physical exercise, and medicinal purposes [4]. Modern usage is generally for recreational and psychoactive effects [5]. Ibotenic acid and muscimol are isoxazole derivatives that resemble the neurotransmitters glutamate and GABA, respectively [6]. Thus, ibotenic acid may induce excitatory effects while muscimol causes sedative effects. There are numerous other chemical constituents in these species of mushrooms that have unknown effects. Muscarine, once thought to be the primary toxin in AM, has been shown to be present only in miniscule quantities [7].