The fly agaric mushroom contains four hallucinogens: muscarine, muscimol, muscazone, and ibotenic acid. In 1912, Henry Dale hypothesized that muscarine or a similar substance was the neurotransmitter at parasympathetic nerve endings, but he and Otto Loewi later isolated the actual transmitter and showed it was acetylcholine, not muscarine. The receptor is now called cholinergic or muscarinic. This discovery led to valuable drugs: pilocarpine for glaucoma and ipratropium for lung diseases.
The history of ergot between 1940 and 1980 was shaped by Arthur Stoll and Albert Hofmann. Their isolation of LSD from ergot sparked hope that it would reveal the cause of schizophrenia and other psychoses, but this expectation was not fulfilled, and Hofmann privately regretted his extensive work on the compound. In contrast, bromocriptine, derived from ergocriptine, became a crucial substance for understanding dopamine receptors in the central nervous system and is widely used to suppress lactation, treat prolactinomas, and manage Parkinson's disease.