Aeruginascin, also known as 4-phosphoryloxy-N,N,N-trimethyltryptamine (4-PO-TMT), is an indoleamine derivative which occurs naturally within the mushrooms Inocybe aeruginascens, Pholiotina cyanopus, and Psilocybe cubensis. Aeruginascin is the N-trimethyl analogue of psilocybin. It is closely related to the frog skin toxin bufotenidine (5-HTQ), a potent serotonin 5-HT3 receptor agonist, but the aeruginascin metabolite 4-HO-TMT (thought to be its active form) shows strong binding at the serotonin 5-HT2 receptors similar to psilocin. Aeruginascin itself has been found to have high affinity for the serotonin 5-HT1A, 5-HT2A, and 5-HT2B receptors, but does not bind to the 5-HT3 receptor. Unlike psilocybin, but similarly to 4-HO-TMT, aeruginascin does not produce the head-twitch response in rodents. It lacks affinity or activation of the mouse 5-HT2A and 5-HT1A receptors. The first scientific literature about the pharmacological effects of aeruginascin is from a study published by Gartz in 1989. Across 23 analyzed cases of accidental hallucinogenic mushroom poisonings, people who had ingested the mushroom Inocybe aeruginascens reported only euphoric experiences. This is in contrast to the slight and in some cases extremely dysphoric experiences reported from the accidental ingestion of non-aeruginascin-containing mushrooms (containing solely psilocybin and psilocin). However, these findings are anecdotal and preliminary.