title: Acquired preference for morphine but no d-amphetamine as a result of saccharine adulteration.
abstract: Consumption of morphine sulfate and d-amphetamine was studied in two groups of rats. In a choice situation, preference for both drugs remained low after 46 days of drinking. In two additional groups morphine and d-amphetamine solutions were prepared with 1% saccharine. Morphine drinking was significantly increased by saccharine adulteration, whereas drinking of amphetamine solutions decreased. Addition of saccharine to morphine solutions increased drinking in more than a simple additive way. Saccharine facilitates the acquisition of drug-directed behavior. The slope of the acquisition trials for the morphine-saccharine group was significantly different from horizontal (O-slope) and significantly different from the slope found for the morphine without saccharine group.
mesh_terms: D000818:Animals; D002755:Choice Behavior; D003913:Dextroamphetamine; D006801:Humans; D008297:Male; D009021:Morphine Dependence; D051381:Rats; D012054:Reinforcement, Psychology; D012439:Saccharin; D012646:Self Administration; D013649:Taste
chemical_list: D012439:Saccharin; D003913:Dextroamphetamine