Modification of conflict behavior by prior experience: effects of training and morphine.
D000818:Animals; D003216:Conditioning, Operant; D003220:Conflict, Psychological / Q000187:drug effects; D004597:Electroshock; D009020:Morphine / Q000494:pharmacology*; D051381:Rats; D012055:Reinforcement Schedule
D009020:Morphine