title: Dose-time motility effects of morphine and methadone in naive or morphinized rats.
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D004361:Drug Tolerance; D006801:Humans; D008297:Male; D008691:Methadone / Q000494:pharmacology*; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D009021:Morphine Dependence / Q000503:physiopathology*; D009043:Motor Activity / Q000187:drug effects*; D051381:Rats; D013997:Time Factors
chemical_list: D009020:Morphine; D008691:Methadone