Morphine and acceptability of putative reinforcers.
Rats were given the opportunity to take one of five concentrations of saccharin solutions. Intake across concentrations generated a preference-aversion curve. Morphine, 2 mg/kg, increased intake of saccharin solutions when rats were 12-hr water deprived or were not deprived. These effects with morphine are opposite to those of naloxone and strengthen the idea that there is opioid involvement in incentive motivation.
D000375:Aging; D000818:Animals; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012054:Reinforcement, Psychology; D012439:Saccharin / Q000494:pharmacology
D009020:Morphine; D012439:Saccharin