Grigson P S
Department of Behavioral Science, College of Medicine, The Pennsylvania State University, Hershey 17033, USA.
Behav Neurosci. 1997 Feb;111(1):129-36.
A new hypothesis (and supporting data) provides a solution to the 25-year-old paradox whereby positively reinforcing drugs of abuse also support a conditioned taste aversion (CTA). The results show that unlike LiCl-induced CTAs, morphine- and cocaine-induced suppression of conditioned stimulus (CS) intake depends on the rewarding properties of the gustatory CS. This finding argues against the long-standing CTA interpretation in favor of a new reward comparison account. That is, rats decrease intake of a gustatory CS following taste-drug pairings because the value of the CS is outweighed by that of a highly reinforcing psychoactive drug. Suppression of CS intake, then, is a consequence of the well-documented positive reinforcing, rather than the hypothetical aversive, properties of drugs of abuse.
一种新的假说（及支持数据）为一个存在了25年的悖论提供了解决方案，即具有正性强化作用的成瘾药物也会引发条件性味觉厌恶（CTA）。结果表明，与氯化锂引发的CTA不同，吗啡和可卡因引发的条件刺激（CS）摄入量抑制取决于味觉CS的奖赏特性。这一发现反驳了长期以来的CTA解释，支持一种新的奖赏比较理论。也就是说，大鼠在味觉与药物配对后减少味觉CS的摄入量，是因为CS的价值被一种具有高度强化作用的精神活性药物的价值所超过。因此，CS摄入量的抑制是滥用药物已被充分证明的正性强化特性的结果，而非假设的厌恶特性的结果。
