Emmett-Oglesby M W, Harris C M, Lane J D, Lal H
Neuropeptides. 1984 Dec;5(1-3):37-40. doi: 10.1016/0143-4179(84)90021-0.
Rats trained to discriminate pentylenetetrazol (PTZ) from saline in a two-lever food-reinforced operant task were given a three-day course of morphine, 15 to 45 mg/kg tid, ip. On the third day naloxone produced dose-dependent generalization to the PTZ stimulus, with 66% of subjects selecting the PTZ lever after the highest dose (0.32 mg/kg). Following termination of morphine injections, generalization of spontaneous withdrawal was tested. Approximately 50% of subjects selected the PTZ lever at 24 and 48 hrs after the last morphine, and by 96 hrs the percentage of subjects selecting the PTZ lever had dropped to 11%. Rats that chose the PTZ lever at 48 hrs were given diazepam, 5.0 mg/kg, which blocked the PTZ-like stimulus. These data demonstrate that morphine withdrawal produces a stimulus with PTZ-like characteristics which can be blocked by an anxiolytic, and they suggest that the PTZ discrimination may have general utility for investigating drug dependence and withdrawal in animals.
在一项双杠杆食物强化操作性任务中接受训练以区分戊四氮（PTZ）和生理盐水的大鼠，接受了为期三天的吗啡疗程，剂量为15至45毫克/千克，每日三次，腹腔注射。在第三天，纳洛酮产生了对PTZ刺激的剂量依赖性泛化，最高剂量（0.32毫克/千克）后66%的受试动物选择了PTZ杠杆。吗啡注射终止后，测试了自发戒断的泛化情况。最后一次注射吗啡后24小时和48小时，约50%的受试动物选择了PTZ杠杆，到96小时时，选择PTZ杠杆的受试动物百分比降至11%。在48小时选择PTZ杠杆的大鼠给予地西泮，剂量为5.0毫克/千克，这阻断了类似PTZ的刺激。这些数据表明，吗啡戒断产生了一种具有类似PTZ特征的刺激，可被抗焦虑药阻断，并且提示PTZ辨别对于研究动物的药物依赖性和戒断可能具有普遍用途。
