Hoffmeister F
J Pharmacol Exp Ther. 1975 Feb;192(2):468-77.
Rhesus monkeys, previously trained to avoid electric shock, pressed a lever to extinguish a light associated with an intravenous drug infusion scheduled to occur 30 seconds after the onset of the light. Each response when the light was on terminated the light for a 1-minute time-out period (avoidance); a response during the infusion terminated the infusion (escape). Under these conditions the monkeys tolerated a high number of saline infusions. Saline was replaced by different doses of chlorpromazine, lysergic acid diethylamide (LSD) and pentobarbital each for six successive daily 2-hour sessions. Infusions of chlorpromazine (5.0-20 mug/kg/infusion) or LSD (1.0-2.5 mug/kg/infusion) generated and maintained avoidance/escape behavior, whereas most of the infusions of pentobarbital (10-100 mu/kg/infusion) were tolerated. In rhesus monkeys with no previous drug experience, chlorpromazine and LSD, but not pentobartital, have negative reinforcing properties.
恒河猴此前经过训练以避免电击，它们按压杠杆以熄灭与静脉注射药物相关的灯光，该药物输注计划在灯光亮起30秒后进行。当灯光亮起时的每次反应会使灯光熄灭1分钟的暂停期（回避）；在输注期间的反应会终止输注（逃避）。在这些条件下，猴子耐受了大量的生理盐水输注。生理盐水被不同剂量的氯丙嗪、麦角酸二乙酰胺（LSD）和戊巴比妥依次替换，每种药物进行连续6天、每天2小时的实验。输注氯丙嗪（5.0 - 20微克/千克/输注）或LSD（1.0 - 2.5微克/千克/输注）会产生并维持回避/逃避行为，而大多数戊巴比妥输注（10 - 100毫克/千克/输注）都能被耐受。在没有药物使用经验的恒河猴中，氯丙嗪和LSD具有负强化特性，而戊巴比妥则没有。
