AUTOSHAPING IV COCAINE SELF-ADMINISTRATION IN RATS - EFFECTS OF NONDRUG ALTERNATIVE REINFORCERS ON ACQUISITION
AUTOSHAPING IV COCAINE SELF-ADMINISTRATION IN RATS - EFFECTS OF NONDRUG ALTERNATIVE REINFORCERS ON ACQUISITION
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DOI：
10.1007/bf02246944
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发表时间：
1993-01-01
影响因子：
3.4
通讯作者：
LAC, ST
中科院分区：
文献类型：
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作者：
CARROLL, ME;LAC, ST
本实验的目的是检验非药物替代增强剂和喂养条件对获得可卡因自我给药的影响。大鼠被自动塑造成按下一个杠杆，导致静脉注射0.2 mg/kg可卡因。在每天连续六次的自动整形过程中，对操纵杆的反应进行了监测。将一个可伸缩的杠杆插入手术室，随机时间为60分钟，S计划每次治疗10次，每小时开始6次。每天，在六次自我整形之后，都会进行6小时的可卡因自我管理。在自我给药期间，操纵杆保持伸展状态，操纵杆上的每一次反应都会导致注射可卡因(0.2 mg/kg)。当连续5天在6小时的自我给药过程中平均输注次数至少为100次时，符合获得可卡因强化行为的标准。每天重复这一过程，直到达到标准或30天后。这些大鼠还被训练在舔水操作的自动饮水器上做出反应，根据每次舔水的反应，该装置会输送0.05毫升的水或葡萄糖和糖精溶液(G+S)。将12-14只大鼠分为5组进行比较。前4组为2×2析因设计，在自动整形开始前，G+S或水在家笼中放置3周，而在自动整形期间，操作室中提供G+S或水。这些小组被限制在每天20克食物，并且所有人都可以免费获得水。第五组只有家笼和操作室中的水，它们可以无限制地获取食物，但没有G+S。结果表明，在操作室中接触G+S溶液大大延迟了自形，其中很大一部分大鼠在30天内不符合自形标准。在家中有G+S的组的数据与在家中只有水的组非常相似；因此，接触G+S的历史不会干扰可卡因自我给药的获得。在可以自由获取食物的人群中，自我塑造的差异很大，但发现食物消耗量和达到获取标准所需的天数之间存在高度的正相关。将摄食量超过20g的大鼠与摄入量不超过20g的另一组大鼠进行比较，发现摄食量的增加明显降低了可卡因自身给药的获得率。这些发现表明，在富含非药物替代增强剂的环境中，可卡因强化行为的获得被延迟或阻止，例如食物和首选液体。
The purpose of this experiment was to examine the effects of a nondrug alternative reinforcer and feeding conditions on the acquisition of cocaine self-administration. Rats were autoshaped to press a lever that resulted in a 0.2 mg/kg IV cocaine infusion. Responses on the lever were monitored during six consecutive autoshaping sessions that occurred each day. A retractable lever was inserted into the operant chamber on a random time 60 s schedule 10 times per session for six sessions that began each hour. Each day the six autoshaping sessions were followed by a 6-h cocaine self-administration session. During self-administration the lever remained extended, and each response on the lever resulted in a cocaine infusion (0.2 mg/kg). The criterion for acquisition of cocaine-reinforced behavior was met when there were 5 consecutive days during which the mean number of infusions during the 6-h self-administration session was at least 100. This procedure was repeated daily until the criterion was met or 30 days elapsed. The rats were also trained to respond on lick-operated automatic drinking devices that delivered 0.05 ml water or a glucose and saccharin solution (G + S) contingent upon each lick response. Five groups of 12-14 rats were compared. The first four groups constituted a 2 x 2 factorial design whereby either G + S or water was available in the home cage for 3 weeks before autoshaping began and G + S or water was available in the operant chamber during autoshaping. These groups were limited to 20 g food per day and all had free access to water. A fifth group had only water available in the home cage and operant chamber, and they had unlimited access to food but no G + S. The results indicated that access to the G + S solution in the operant chamber substantially delayed autoshaping, and a large percentage of these rats did not meet the autoshaping criterion within 30 days. The data from groups that had G + S in the home cage were very similar to those that had only water in the home cage; thus, a history of access to G + S did not interfere with acquisition of cocaine self-administration. Autoshaping in the group that had free access to food was highly variable, but a high positive correlation was found between the amount of food consumed and the number of days taken to meet the acquisition criterion. When the rats from the group that consumed over 20 g were compared to the rats in another group that were limited to 20 g and had no G + S, it was found that the increased food intake markedly decreased the rate of acquisition of cocaine self-administration. These findings indicate that acquisition of cocaine-reinforced behavior is delayed or prevented in environments enriched with nondrug alternative reinforcers such as food and a preferred liquid.