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