title: Development of behavioral tolerance to morphine and methadone using the schedule-controlled behavior of the pigeon.
mesh_terms: D000818:Animals; D001070:Appetitive Behavior / Q000187:drug effects; D001522:Behavior, Animal / Q000187:drug effects*; D010856:Columbidae; D004361:Drug Tolerance; D006801:Humans; D008297:Male; D008691:Methadone / Q000494:pharmacology*; D009020:Morphine / Q000494:pharmacology*; D012055:Reinforcement Schedule; D013375:Substance Withdrawal Syndrome
chemical_list: D009020:Morphine; D008691:Methadone