There is recent evidence that cocaine, nicotine, and their conditioned stimuli have the ability to enhance memory consolidation. The present study compared the effects of post-training heroin and of a heroin contextual conditioned stimulus (CS+) on consolidation of object recognition memory and investigated the roles of opioid and beta-adrenergic receptors in heroin/CS+ memory modulation by co-administering the respective antagonists, naltrexone (NTX) and propranolol (PRO). Three experiments were performed in male Sprague-Dawley rats demonstrating that immediate, but not delayed, post-sample exposure to heroin (0.3, 1 mg/kg), or exposure (30 min) to a contextual CS+ paired with 1 mg/kg heroin (5 pairings, each 120 min), equally enhanced object memory. Importantly, while the memory enhancing effects of 1 mg/kg heroin and of the contextual CS+ were not altered by post-training co-administration of 3 mg/kg naltrexone, they were blocked by post-training co-administration of 10 mg/kg propranolol. Taken together, these data suggest that a context paired with heroin shares the memory enhancing effect of heroin itself and that these unconditioned and conditioned drug stimuli may modulate memory through the activation of beta-noradrenergic receptors.

中文翻译：

---

海洛因和海洛因条件刺激对物体记忆巩固的调节：阿片类药物和去甲肾上腺素能系统的作用

最近有证据表明可卡因、尼古丁和它们的条件刺激具有增强记忆巩固的能力。本研究比较了训练后海洛因和海洛因情境条件刺激 (CS+) 对巩固物体识别记忆的影响，并通过共同给药分别研究了阿片类药物和 β-肾上腺素能受体在海洛因/CS+ 记忆调节中的作用拮抗剂，纳曲酮（NTX）和普萘洛尔（PRO）。在雄性 Sprague-Dawley 大鼠中进行了三项实验，表明样本后立即但不延迟地暴露于海洛因（0.3，1 毫克/千克），或暴露（30 分钟）到与 1 毫克/千克海洛因配对的上下文 CS+ （5 对，每对 120 分钟），同样增强了对象记忆。重要的，虽然 1 mg/kg 海洛因和上下文 CS+ 的记忆增强效果不会被 3 mg/kg 纳曲酮的训练后共同给药改变，但它们被训练后共同给药 10 mg/kg 心得安阻断。综上所述，这些数据表明，与海洛因配对的环境具有海洛因本身的记忆增强作用，并且这些无条件和有条件的药物刺激可能通过激活 β-去甲肾上腺素能受体来调节记忆。