Ettenberg A, Horvitz J C
Department of Psychology, University of California, Santa Barbara 93106.
Pharmacol Biochem Behav. 1990 Nov;37(3):465-9. doi: 10.1016/0091-3057(90)90014-9.
Thirsty animals were trained to traverse a straight runway once each day for a reward consisting of 100 licks from a water-filled drinking tube. Once running speeds had stabilized, single daily extinction trials were initiated during which no water reinforcement was provided in the goal box. Extinction trials continued until running had slowed to levels approximately half of that observed during reinforced trials. A single treatment trial was then conducted in which some animals found water in the goal box and others continued to find an empty water bottle. Those subjects that were reinforced on treatment day subsequently demonstrated a reinstatement of their operant running response on the very next trial (i.e., 24 hr later). However, pretreatment with 1.0 mg/kg (but not 0.5 mg/kg) of the dopamine antagonist drug, pimozide, attenuated this response-reinstating effect of water-reinforcement. This action of pimozide was not likely a consequence of some residual sedative or motor incapacitation since a) the test day was conducted 24 hr after the treatment day by which time the pharmacological actions of the drug had greatly subsided; b) a Motor Control group administered pimozide after the reinforced trial exhibited normal response-reinstatement 24 hr later on Test Day; and c) on treatment day, pimozide did not reliably attenuate running times, latency to initiate drinking, nor the rate of licking behavior. Together, these data suggest that dopamine receptor antagonism can produce an attenuation in the reinforcing efficacy of water.
口渴的动物每天接受训练，让它们沿直线跑道跑一次，以获取奖励，奖励是从装满水的饮水管中舔100次。一旦奔跑速度稳定下来，就开始进行每日单次的消退试验，在此期间目标箱中不提供水作为强化物。消退试验持续进行，直到奔跑速度减慢到强化试验期间观察到的速度的大约一半。然后进行一次单次治疗试验，其中一些动物在目标箱中找到了水，而另一些动物继续发现水瓶是空的。那些在治疗日得到强化的受试者随后在紧接着的下一次试验（即24小时后）表现出其操作性奔跑反应的恢复。然而，用1.0毫克/千克（而不是0.5毫克/千克）的多巴胺拮抗剂药物匹莫齐特进行预处理，减弱了水强化的这种反应恢复效应。匹莫齐特的这种作用不太可能是某种残留镇静或运动功能丧失的结果，因为：a）试验日在治疗日后24小时进行，此时药物的药理作用已大大消退；b）在强化试验后给予匹莫齐特的运动控制组在试验日24小时后表现出正常的反应恢复；c）在治疗日，匹莫齐特并没有可靠地减弱奔跑时间、开始饮水的潜伏期或舔舐行为的速率。总之，这些数据表明多巴胺受体拮抗作用可导致水的强化效力减弱。
