Calcagnetti D J, Reid L D
Pharmacol Biochem Behav. 1983 Apr;18(4):567-9. doi: 10.1016/0091-3057(83)90282-4.
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.
给予大鼠选择五种不同浓度糖精溶液之一的机会。不同浓度下的摄入量产生了一条偏好-厌恶曲线。当大鼠被剥夺12小时水分或未被剥夺水分时，2毫克/千克的吗啡会增加糖精溶液的摄入量。吗啡的这些作用与纳洛酮的作用相反，强化了阿片类物质参与动机激励的观点。
