Grilly D M, Grogan T W
Psychology Department, Cleveland State University, OH 44115.
Pharmacol Biochem Behav. 1990 Jan;35(1):269-71. doi: 10.1016/0091-3057(90)90238-d.
Rats were food-reinforced for pressing one of two levers in an operant chamber, with the correct lever being indicated by the position of a briefly illuminated light. After stable accuracy levels were achieved, the rats were tested after an injection of either saline or cocaine (2.5 mg/kg) under two conditions. In the "low arousal" condition, animals were tested during the light phase of a 12-hr light-dark cycle and were fed approximately 5 hr prior to testing. In the "high arousal" condition, animals were tested during the dark phase after approximately 28-hr food deprivation. As expected, accuracy was higher and median choice and food retrieval latencies were shorter under the high arousal condition. Contrary to predictions, cocaine enhanced accuracy under both conditions. These results indicate that cocaine-enhanced performance in some tasks is not necessarily dependent on the animal performing at suboptimal arousal levels.
在一个操作性条件反射箱中，大鼠通过按压两个杠杆中的一个来获取食物奖励，正确的杠杆由短暂亮起的灯光位置指示。在达到稳定的准确率水平后，在两种条件下对大鼠注射生理盐水或可卡因（2.5毫克/千克）后进行测试。在“低唤醒”条件下，动物在12小时明暗循环的光照阶段进行测试，并且在测试前约5小时喂食。在“高唤醒”条件下，动物在大约28小时食物剥夺后的黑暗阶段进行测试。正如预期的那样，在高唤醒条件下准确率更高，中位选择和获取食物的潜伏期更短。与预测相反，可卡因在两种条件下均提高了准确率。这些结果表明，可卡因在某些任务中增强的表现不一定依赖于动物在次优唤醒水平下执行任务。
