Rats deprived of REM sleep for three days showed a stronger serotonin syndrome and more head shakes than control rats when given serotonin precursors (L-5-hydroxytryptophan or L-tryptophan, with or without MAO inhibitors). However, REM deprivation did not change the rats' response to the serotonin agonists MeO-DMT (0.75-6.0 mg/kg) or quipazine (2.4-6.0 mg/kg), and reduced their response to lower doses of quipazine (0.3-1.25 mg/kg). The findings suggest that increased serotonin turnover during REM deprivation may enhance precursor effects, while reduced responsiveness to quipazine may reflect receptor hyposensitivity from intense activation.
Two ethnobotanical surveys among the Krahô Indians of Tocantins State and Quilombola descendants of former slaves in Mato Grosso State, Brazil, documented 169 plants used in ritual healing ceremonies for central nervous system ailments. These plants were prepared in 345 prescriptions for 68 conditions classified as tonics, analgesics, anorectics, hallucinogens, and anxiolytics. The work discusses the taxonomic families of the plants, common therapeutic indications, and types of healing rituals.