Incentive Learning for Morphine-Associated Stimuli During Protracted Abstinence Increases Conditioned Drug Preference

摘要: Previous studies from our laboratory found that rats express increased preference for drug-paired stimuli following 2 or 5 weeks of protracted abstinence chronic drug exposure as compared with naive animals. Here, we show this morphine place depends upon experiencing drug-stimulus pairings specifically in the abstinent state, indicating a critical role incentive learning. Male Sprague Dawley were initially conditioned (8 mg/kg) and then made dependent on (by subcutaneous pellets) subjected to forced abstinence. Place was tested every 1–2 no additional drug-cue conditioning. In paradigm, there difference between morphine-pelleted (dependent) placebo-pelleted (non-dependent) at any time during (up 6 weeks). However, these same expressed significantly when they subsequently re-conditioned Placebo-pelleted did not enhanced after re-conditioning. These findings reveal learning has key is experienced This indicates involved only instrumental responding (as previously reported), but also updating Pavlovian-conditioned responses morphine-associated stimuli. Therefore, direct consequence negative affective state abstinence, instead reflects acquisition morphine-stimulus associations results indicate that, development addiction humans, drug-associated acquire increasingly stronger properties each are re-experienced.