McNally Gavan P, Pigg Michael, Weidemann Gabrielle
School of Psychology, University of New South Wales, Sydney, NSW, Australia.
Behav Neurosci. 2004 Feb;118(1):111-20. doi: 10.1037/0735-7044.118.1.111.
Injection of the opioid receptor antagonist naloxone facilitated acquisition of fear to contextual and auditory conditioned stimuli (CSs) in Experiments 1A and 1B. Experiment 2 showed that prior conditioning to a distinctive context blocked conditioning to an auditory CS. Blocking of CS fear was prevented by administrations of naloxone or increases in footshock intensity. Blocking of CS fear was facilitated by decreases in footshock intensity in a naloxone-reversible manner. Experiment 3 showed that compound conditioning of two CSs, each previously and separately paired with shock, produced overexpectation of fear that was reversed by naloxone. These results are consistent with a role for opioid receptors controlling Pavlovian association formation by regulating the discrepancy (lambda - SigmaV) described by R. A. Rescorla and A. R. Wagner (1972).
在实验1A和1B中，注射阿片受体拮抗剂纳洛酮促进了对情境性和听觉条件刺激（CSs）的恐惧习得。实验2表明，预先对一个独特情境进行条件作用会阻断对听觉CS的条件作用。纳洛酮给药或增加足部电击强度可防止CS恐惧的阻断。以纳洛酮可逆的方式降低足部电击强度可促进CS恐惧的阻断。实验3表明，对两个CS进行复合条件作用，每个CS之前分别与电击配对，产生了对恐惧的过度预期，而纳洛酮可逆转这种过度预期。这些结果与阿片受体通过调节R. A. 雷斯克拉和A. R. 瓦格纳（1972年）所描述的差异（λ - ΣV）来控制巴甫洛夫联想形成的作用一致。
