Peters Jamie, De Vries Taco J
Department of Anatomy and Neurosciences, Neuroscience Campus Amsterdam, VU University medical center, 1081BT, Amsterdam, The Netherlands,
Psychopharmacology (Berl). 2014 Jan;231(2):447-53. doi: 10.1007/s00213-013-3258-7. Epub 2013 Sep 12.
Novel stimuli paired with exposure to addictive drugs can elicit approach through Pavlovian learning. While such approach behavior, or sign tracking, has been documented for cocaine and alcohol, it has not been shown to occur with opiate drugs like heroin. Most Pavlovian conditioned approach paradigms use an operandum as the sign, so that sign tracking can be easily automated.
We were interested in assessing whether approach behavior occurs to an audiovisual cue paired with an intravenous heroin infusion. If so, would this behavior exhibit characteristics of other Pavlovian conditioned behaviors, such as extinction and spontaneous recovery?
Rats were repeatedly exposed to an audiovisual cue, similar to that used in standard self-administration models, along with an intravenous heroin infusion. Sign tracking was measured in an automated fashion by analyzing motion pixels within the cue zone during each cue presentation.
We were able to observe significant sign tracking after only five pairings of the conditioned stimulus (CS) with the unconditioned stimulus (US). This behavior rapidly extinguished over 2 days, but exhibited pronounced spontaneous recovery 3 weeks later.
We conclude that sign tracking measured by these methods exhibits all the characteristics of a classically conditioned behavior. This model can be used to examine the Pavlovian component of drug memories, alone, or in combination with self-administration methods.
与成瘾性药物接触配对的新刺激可通过巴甫洛夫式学习引发趋近行为。虽然这种趋近行为，即信号追踪，已在可卡因和酒精的研究中得到证实，但在海洛因等阿片类药物中尚未发现。大多数巴甫洛夫式条件性趋近范式使用操作物作为信号，以便信号追踪能够轻松实现自动化。
我们感兴趣的是评估与静脉注射海洛因配对的视听线索是否会引发趋近行为。如果是这样，这种行为是否会表现出其他巴甫洛夫式条件性行为的特征，如消退和自发恢复？
将大鼠反复暴露于与标准自我给药模型中使用的类似的视听线索，并同时进行静脉注射海洛因。通过在每次线索呈现期间分析线索区域内的运动像素，以自动化方式测量信号追踪。
在条件刺激（CS）与非条件刺激（US）仅配对五次后，我们就能观察到显著的信号追踪。这种行为在2天内迅速消退，但在3周后表现出明显的自发恢复。
我们得出结论，通过这些方法测量的信号追踪表现出经典条件性行为的所有特征。该模型可用于单独或与自我给药方法相结合来研究药物记忆的巴甫洛夫成分。
