Cocaine and morphine-induced place conditioning in adolescent and adult rats
Cocaine and morphine-induced place conditioning in adolescent and adult rats
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DOI：
10.1016/s0031-9384(99)00225-5
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发表时间：
2000-02-01
影响因子：
2.9
通讯作者：
Spear, LP
中科院分区：
文献类型：
--
作者：
Campbell, JO;Wood, RD;Spear, LP
大鼠青春期的特点是新奇探索行为的改变，以及对许多滥用药物的行为反应的改变。这些变化可能预示着滥用药物的奖励价值会发生变化。本实验考察了青春期(34-37天)大鼠在药物诱导的吗啡(0、2.5或5 mg/kg；实验I)和可卡因(0、5或10 mg/kg；实验II和III)诱导的位置条件反射的表达上是否与成年大鼠不同。动物接受多天的条件反射，24小时后进行无药物CPP试验。所有药物在进入CS隔间之前立即进行腹膜腔内注射，而车辆注射则在暴露于CS室之前进行。对于这两种药物，当药物暴露与非首选药室配对时，青少年和成年人在位置条件反射方面没有显著差异。当可卡因与首选或非首选隔室配对时(实验III)，观察到的位置条件作用的大小在青少年和成年人之间没有差异。在目前的实验中，药物诱导的位置条件反射表达的年龄差异不太可能是天花板效应的结果，因为数据表明，所使用的剂量包括接近阈值的剂量。虽然这些发现需要使用其他评估药物奖励的方法来证实，然后才能得出结论，青少年和成年大鼠对吗啡和可卡因的奖赏效应表现出类似的敏感性，但目前的数据显示，青少年和成人之间在吗啡或可卡因的位置条件作用大小方面没有差异；(C)2000 Elsevier Science Inc.保留所有权利。
The periadolescent period in the rat is characterized by alterations in novelty seeking and exploratory behavior, as well as changes in the behavioral responsiveness to many drugs of abuse. These alterations may be predictive of alterations in the reward value of drugs of abuse. The present experiments examined whether adolescent rats (34-37 days old) differ from their adult counterparts in the expression of drug-induced place conditioning for morphine (0, 2.5, or 5 mg/kg; Experiment I) and cocaine (0, 5, or 10 mg/kg; Experiments II and III). Animals received multiple conditioning days, followed 24 h later by a drug-free CPP test. All drugs were given intraperitoneally immediately prior to confinement in the CSS compartment, while vehicle injections were given prior to exposure to the CS- chamber. For both drugs, there were no significant differences between adolescents and adults in amount of place conditioning seen when drug exposure was paired with the nonpreferred chamber. When cocaine was paired with either the preferred or nonpreferred compartment (Experiment III), again, the magnitude of the place conditioning observed did not differ between adolescents and adults. The lack of age differences in expression of drug-induced place conditioning in the present experiments is not likely a result of ceiling effects, because the data suggest that the doses used included near-threshold doses. Although these findings need to be confirmed using other approaches for assessing drug reward before concluding that adolescent and adult rats exhibit similar sensitivity to the rewarding effects of morphine and cocaine, the current data revealed no differences between adolescents and adults in the magnitude of place conditioning expressed for morphine or cocaine; (C) 2000 Elsevier Science Inc. All rights reserved.