Weiss Stanley J, Kearns David N
Department of Psychology, American University, Washington, District of Columbia, USA.
Behav Pharmacol. 2016 Apr;27(2-3 Spec Issue):293-300. doi: 10.1097/FBP.0000000000000220.
The present experiment investigated the extent to which the A+/AB- conditioned inhibition procedure could counteract an excitatory drug-related conditioning history. In two groups of rats, a light stimulus was established as a signal for the absence of cocaine. For the History group, the light had previously been a discriminative stimulus (S) that occasioned cocaine self-administration and could thus be classified as a cocaine excitor. In comparison, the No-History group first encountered the light during conditioned inhibition training. During conditioned inhibition training, both groups self-administered cocaine during tone as well as during click Ss, whereas drug seeking was eliminated in click-plus-light, wherein cocaine was not available (A+/AB-). Drug seeking was essentially eliminated in both groups. Nevertheless, on a summation test the light reduced cocaine seeking occasioned by the tone S by 95% in the No-History group, but by less than 50% in the History group. This summation test result showed that the effects of a drug-related history persisted even after the light was converted into an effective conditioned inhibitor on the training baseline through the powerful A+/AB- procedure. Future research should seek procedures that produce even stronger conditioned inhibition that eliminates such residual 'silent' drug excitation, the 'ghost in the addict'.
本实验研究了A+/AB-条件性抑制程序能够抵消与药物相关的兴奋性条件作用历史的程度。在两组大鼠中，将光刺激确立为无可卡因的信号。对于有条件作用历史组，该光先前是一种辨别性刺激（S），可引发可卡因自我给药，因此可归类为可卡因兴奋性刺激。相比之下，无条件作用历史组在条件性抑制训练期间首次接触该光。在条件性抑制训练期间，两组在纯音以及点击刺激期间均自我给药可卡因，而在点击加光刺激期间（此时无可卡因），觅药行为被消除（A+/AB-）。两组的觅药行为基本都被消除。然而，在一个总和测试中，光使无条件作用历史组中由纯音刺激引发的可卡因觅药行为减少了95%，但在有条件作用历史组中减少幅度不到50%。该总和测试结果表明，即使通过强大的A+/AB-程序在训练基线时将光转化为有效的条件性抑制剂后，与药物相关的历史影响仍然存在。未来的研究应寻找能产生更强条件性抑制的程序，以消除这种残留的“隐性”药物兴奋，即“成瘾者心中的幽灵”。
