Gallagher M, Kapp B S, McNall C L, Pascoe J P
Pharmacol Biochem Behav. 1981 Apr;14(4):497-505. doi: 10.1016/0091-3057(81)90309-9.
Opiate agents were administered into the central nucleus of the amygdala complex of rabbits prior to either classical conditioning or pseudoconditioning of heart rate responding. Compared to control groups, opiate administration into the central nucleus did not significantly alter baseline heart rate, heart rate responding during habituation trials to presentations of the conditioned stimulus alone, or heart rate responding during the pseudoconditioning procedure. However, opiate administration altered the acquisition of a conditioned bradycardia response during classical conditioning trials in which the offset of the conditioned stimulus was coincident with the presentation of an aversive unconditioned stimulus. the opiate agonist levorphanol (5.0 nmole) significantly impaired the acquisition of the conditioned bradycardia response. This effect was observed to be stereospecific and blocked by concurrent administration of the opiate antagonist naloxone (2.5 nmole). Naloxone (2.5 nmole) administration alone significantly increased the magnitude of the conditioned bradycardia response. These effects produced by opiate administration into the central nucleus were not observed following administration of the same agents into sites 1-2 mm dorsal to the central nucleus.
在对兔子心率反应进行经典条件反射或假条件反射之前，将阿片类药物注入其杏仁核复合体的中央核。与对照组相比，向中央核注入阿片类药物并未显著改变基线心率、在仅对条件刺激进行呈现的习惯化试验期间的心率反应，或在假条件反射过程中的心率反应。然而，在经典条件反射试验中，当条件刺激的终止与厌恶非条件刺激的呈现同时发生时，注入阿片类药物改变了条件性心动过缓反应的习得。阿片类激动剂左啡诺（5.0纳摩尔）显著损害了条件性心动过缓反应的习得。观察到这种效应具有立体特异性，并被同时给予阿片类拮抗剂纳洛酮（2.5纳摩尔）所阻断。单独给予纳洛酮（2.5纳摩尔）显著增加了条件性心动过缓反应的幅度。将相同药物注入中央核背侧1 - 2毫米处的位点后，未观察到向中央核注入阿片类药物所产生的这些效应。
