title: Effect of psilocin on extracellular dopamine and serotonin levels in the mesoaccumbens and mesocortical pathway in awake rats.
abstract: Psilocin (3-[2-(dimethylamino)ethyl]-1H-indol-4-ol) is a hallucinogenic component of the Mexican mushroom Psilocybe mexicana and a skeletal serotonin (5-HT) analogue. Psilocin is the active metabolite of psilocybin (3-[2-(dimethylamino)ethyl]-1H-indol-4-yl dihydrogen phosphate). In the present study, we examined the effects of systemically administered psilocin on extracellular dopamine and 5-HT concentrations in the ventral tegmental area (VTA), nucleus accumbens, and medial prefrontal cortex of the dopaminergic pathway in awake rats using in vivo microdialysis. Intraperitoneal administration of psilocin (5, 10 mg/kg) significantly increased extracellular dopamine levels in the nucleus accumbens. Psilocin did not affect the extracellular 5-HT level in the nucleus accumbens. Conversely, systemic administration of psilocin (10 mg/kg) significantly increased extracellular 5-HT levels in the medial prefrontal cortex of rats, but dopamine was decreased in this region. However, neither extracellular dopamine nor 5-HT levels in the VTA were altered by administration of psilocin. Behaviorally, psilocin significantly increased the number of head twitches. Thus, psilocin affects the dopaminergic system in the nucleus accumbens. In the serotonergic system, psilocin contribute to a crucial effect in the medial prefrontal cortex. The present data suggest that psilocin increased both the extracellular dopamine and 5-HT concentrations in the mesoaccumbens and/or mesocortical pathway.
authors.affiliation: Department of Medicinal Pharmacology, Showa Pharmaceutical University.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Sakashita
authors.forename: Kenji
authors.initials: K
authors.lastname: Abe
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Katagiri
authors.forename: Toshie
authors.initials: T
authors.lastname: Kambe
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Saitoh
authors.forename: Iku
authors.initials: I
authors.lastname: Utsunomiya
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Horiguchi
authors.forename: Kyoji
authors.initials: K
authors.lastname: Taguchi
mesh_terms: D000818:Animals; D004298:Dopamine / Q000378:metabolism*; D006213:Hallucinogens / Q000494:pharmacology*; D008297:Male; D009714:Nucleus Accumbens / Q000187:drug effects* / Q000378:metabolism; D017397:Prefrontal Cortex / Q000187:drug effects* / Q000378:metabolism; D011562:Psilocybin / Q000031:analogs & derivatives* / Q000494:pharmacology; D017208:Rats, Wistar; D012701:Serotonin / Q000378:metabolism*; D017557:Ventral Tegmental Area / Q000187:drug effects / Q000378:metabolism
chemical_list: D006213:Hallucinogens; D011562:Psilocybin; D012701:Serotonin; C009105:psilocin; D004298:Dopamine