Grilly D M, Gowans G C
Psychopharmacology (Berl). 1986;88(4):500-4. doi: 10.1007/BF00178515.
Alterations in shock discrimination accuracy in the rat, indicative of hyperalgesia, have been noted 1-3 days following a single injection of morphine. To establish the extent to which these "withdrawal-like" effects were specific to the shock discrimination paradigm, rats were trained in two separate discrimination tasks. The discriminative stimuli (SD,s) for correct lever presses were mild electric shocks of different intensities in one task and were short duration lights over the levers in the other. After achieving comparable accuracy levels in the two tasks, the animals were injected SC with 30 mg/kg morphine sulfate and performance levels assessed 1, 2, 3, and 7 days later. Shock discrimination accuracy was significantly enhanced on post-morphine day 2, while accuracy in the light position task was not significantly affected on any of the post-morphine test days. The results indicated that increased pain sensitivity, as well as other signs of dependence, can occur following acute exposure to morphine.
单次注射吗啡后1至3天，已观察到大鼠对电击辨别准确性的改变，这表明存在痛觉过敏。为了确定这些“戒断样”效应在多大程度上特定于电击辨别范式，对大鼠进行了两项独立的辨别任务训练。在一项任务中，正确按压杠杆的辨别刺激（SDs）是不同强度的轻度电击，而在另一项任务中是杠杆上方持续时间较短的灯光。在两项任务中达到可比的准确性水平后，给动物皮下注射30mg/kg硫酸吗啡，并在1、2、3和7天后评估其表现水平。吗啡注射后第2天，电击辨别准确性显著提高，而在吗啡注射后的任何测试日，灯光位置任务的准确性均未受到显著影响。结果表明，急性接触吗啡后可能会出现疼痛敏感性增加以及其他依赖迹象。
