Grilly D M, Genovese R F, Nowak M J
Psychopharmacology (Berl). 1980;70(2):213-7. doi: 10.1007/BF00435317.
The effects of 2 and 4 mg/kg morphine sulfate, 0.5 and 1 mg/kg d-amphetamine sulfate, and 6 and 12 mg/kg pentobaribital sodium were tested in rats in two different discrete-trial two-choice discrimination tasks. The discriminative stimuli for one task were high and low intensity shocks. In the other, correct choices were signaled by the position of a brief light flash. Morphine (4 mg/kg) significantly disrupted performance of both tasks, with more reliable disturbance occurring in the shock discrimination animals. Pentobarbital (12 mg/kg), while exerting noticeable effects on gross motor behavior, had little effect on discrimination performance; d-amphetamine (1 mg/kg) was disruptive of discrimination performance in only some animals. The results indicate that much of the effect of relatively low doses of morphine on the shock discrimination performance of rats may be due not to its putative specific antinociceptive properties, but to alterations in conceptual-judgmental processes or decreases in motivation (e.g., hunger) unrelated to pain.
在两项不同的离散试验二选一辨别任务中，对大鼠测试了2毫克/千克和4毫克/千克硫酸吗啡、0.5毫克/千克和1毫克/千克硫酸右旋苯丙胺以及6毫克/千克和12毫克/千克戊巴比妥钠的作用。其中一项任务的辨别刺激是高强度和低强度电击。在另一项任务中，正确选择由短暂闪光的位置发出信号。吗啡（4毫克/千克）显著干扰了两项任务的表现，电击辨别任务的动物中出现了更可靠的干扰。戊巴比妥（12毫克/千克）虽然对总体运动行为有明显影响，但对辨别表现影响很小；右旋苯丙胺（1毫克/千克）仅在一些动物中干扰辨别表现。结果表明，相对低剂量吗啡对大鼠电击辨别表现的大部分影响可能不是由于其假定的特定抗伤害感受特性，而是由于概念判断过程的改变或与疼痛无关的动机（如饥饿）降低。
