Hallucinogenic compounds in the form of, or extracted from, plants and mushrooms have been used for centuries, mostly in religious rituals. Almost all hallucinogens contain [[nitrogen]] and are classified as [[alkaloids]]. Many hallucinogens have chemical structures similar to those of [[neurotransmitters]] (e.g., acetylcholine-, serotonin-, or catecholamine-like) and temporarily interfere with their action or bind their receptor sites, but the exact mechanisms by which these substances exert their hallucinogenic effects remain unclear. | Hallucinogenic compounds in the form of, or extracted from, plants and mushrooms have been used for centuries, mostly in religious rituals. Almost all hallucinogens contain [[nitrogen]] and are classified as [[alkaloids]]. Many hallucinogens have chemical structures similar to those of [[neurotransmitters]] (e.g., acetylcholine-, serotonin-, or catecholamine-like) and temporarily interfere with their action or bind their receptor sites, but the exact mechanisms by which these substances exert their hallucinogenic effects remain unclear. |