Mariathasan E A, Stolerman I P
Department of Psychiatry, Institute of Psychiatry, London, UK.
Drug Alcohol Depend. 1994 Apr;35(2):117-25. doi: 10.1016/0376-8716(94)90118-x.
These experiments aim to probe the role of different functional relationships between drugs, responses and reinforcers in studies on the discrimination of drug mixtures. Two-lever discriminations based on mixtures of (+)-amphetamine (0.4 mg/kg) plus pentobarbitone (10 mg/kg) have been compared in three groups of rats (n = 8) trained to discriminate: (i) the mixture from saline, called the AND-discrimination; (ii) either the mixture, amphetamine or pentobarbitone from saline, the OR-discrimination; (iii) the mixture from either amphetamine or pentobarbitone, the AND-OR-discrimination. The rats were trained in a two-bar operant conditioning procedure with a tandem schedule of food reinforcement. The rats trained on the AND procedure acquired the discrimination more rapidly than the rats trained on the other two procedures, but after 60 training sessions, all discriminations were performed with similar (90-94%) accuracy. In rats trained under the AND and the OR procedures, there was full generalization from the mixture to the largest doses used of either amphetamine or pentobarbitone. In contrast, in rats trained under the AND-OR procedure, there was no generalization from the mixture to any dose of either drug separately. The training procedures for the OR and the AND-OR groups were changed to AND-discrimination training; the effects of the different previous histories were found to persist for a prolonged period, despite the fact that training conditions were now the same in all groups. The effects of the drugs on rates of responding were also influenced by the previous training history. Thus, using different training procedures to alter functional relationships can substantially and persistently influence the major characteristics of a discrimination based on a mixture of drugs.
这些实验旨在探究在药物混合物辨别研究中，药物、反应和强化物之间不同功能关系的作用。在三组大鼠（每组n = 8）中比较了基于（+）-苯丙胺（0.4毫克/千克）加戊巴比妥（10毫克/千克）混合物的双杠杆辨别实验。这些大鼠被训练进行辨别：（i）混合物与生理盐水，称为“与”辨别；（ii）混合物、苯丙胺或戊巴比妥与生理盐水，称为“或”辨别；（iii）混合物与苯丙胺或戊巴比妥中的一种，称为“与-或”辨别。大鼠通过双杆操作性条件反射程序进行训练，采用串联式食物强化计划。接受“与”程序训练的大鼠比接受其他两种程序训练的大鼠更快地学会了辨别，但在60次训练后，所有辨别的准确率相似（90-94%）。在接受“与”和“或”程序训练的大鼠中，从混合物到所使用的最大剂量的苯丙胺或戊巴比妥都有完全的泛化。相比之下，在接受“与-或”程序训练的大鼠中，从混合物到任何一种药物的单独剂量都没有泛化。“或”组和“与-或”组的训练程序改为“与”辨别训练；尽管所有组现在的训练条件相同，但发现不同的先前训练历史的影响会持续很长时间。药物对反应率的影响也受先前训练历史的影响。因此，使用不同的训练程序来改变功能关系可以显著且持久地影响基于药物混合物的辨别的主要特征。
