Intragastric self-administration of morphine as a measure of addiction.
D000818:Animals; D003216:Conditioning, Operant; D004195:Disease Models, Animal; D004327:Drinking Behavior; D004750:Enteral Nutrition; D006801:Humans; D008297:Male; D009020:Morphine / Q000008:administration & dosage*; D009021:Morphine Dependence; D051381:Rats; D012054:Reinforcement, Psychology; D019966:Substance-Related Disorders
D009020:Morphine