 <unk> , discovered in 1869 , was long thought to be the active hallucinogenic agent in A. muscaria . <unk> binds with <unk> acetylcholine receptors leading to the <unk> of neurons bearing these receptors . The levels of muscarine in Amanita muscaria are minute when compared with other poisonous fungi such as Inocybe <unk> , the small white <unk> species C. <unk> and C. <unk> . The level of muscarine in A. muscaria is too low to play a role in the symptoms of poisoning . 
