title: Environmental influences upon morphine or d-amphetamine induced suppression of operant behavior.
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D003216:Conditioning, Operant; D003864:Depression, Chemical; D003913:Dextroamphetamine / Q000494:pharmacology*; D004780:Environment, Controlled; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D051381:Rats; D012055:Reinforcement Schedule
chemical_list: D009020:Morphine; D003913:Dextroamphetamine