Siegel S, Hinson R E, Krank M D
J Exp Psychol Anim Behav Process. 1978 Apr;4(2):188-96. doi: 10.1037//0097-7403.4.2.188.
According to a model of morphine tolerance, which emphasizes Pavlovian conditioning principles, tolerance results from an association between predrug environmental cues and the systemic effects of the drug. To assess this model, groups of rats were administered morphine on either three or nine occasions, with a complex environmental stimulus either paired or not paired with each injection. Control groups had equivalent experience with the environmental cue and injection procedure, but the injected substance was physiological saline. Subsequently, the analgesic effect of the opiate was tested in all subjects following administration of the drug in conjunction with the environmental cue. As expected on the basis of the conditioning model of tolerance, subjects with a pretest history of paired morphine administrations displayed analgesic tolerance, but subjects with a pretest history of unpaired administration displayed no evidence of such tolerance. The results suggest that prior demonstrations that the display of morphine tolerance is specific to the drug administration environment may be readily interpreted by a conditioning analysis of tolerance.
根据一种强调巴甫洛夫条件反射原理的吗啡耐受性模型，耐受性源于用药前环境线索与药物全身效应之间的关联。为了评估该模型，将几组大鼠分别给予吗啡3次或9次，每次注射时伴有复杂的环境刺激，刺激与注射或配对或不配对。对照组对环境线索和注射程序有相同的经历，但注射的物质是生理盐水。随后，在所有受试者身上，将药物与环境线索一起给药后，测试阿片类药物的镇痛效果。正如基于耐受性条件反射模型所预期的那样，有配对吗啡给药预测试历史的受试者表现出镇痛耐受性，但有未配对给药预测试历史的受试者没有显示出这种耐受性的证据。结果表明，先前关于吗啡耐受性表现特定于给药环境的证明，可能很容易通过耐受性的条件反射分析来解释。
