Low dose nicotine treatment during early adolescence increases subsequent cocaine reward
Low dose nicotine treatment during early adolescence increases subsequent cocaine reward
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DOI：
10.1016/j.ntt.2006.10.012
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发表时间：
2007-01-01
影响因子：
2.9
通讯作者：
Leslie, Frances M.
中科院分区：
文献类型：
--
作者：
McQuown, Susan C.;Belluzzi, James D.;Leslie, Frances M.
青少年是开始使用毒品的关键时期，从烟草和酒精开始，发展到大麻和其他非法毒品。这些发现表明，烟草和酒精是“入门”毒品，使成熟的奖赏通路对可卡因等非法物质的影响变得敏感。为了验证这一假设，我们研究了低剂量尼古丁预处理是否比成人更能改变青少年对可卡因自我给药的获取。雄性和雌性Sprague-Dawley大鼠，出生后28天或86天，每天两次静脉注射尼古丁（0.03 mg/kg/0.1 ml）或生理盐水，连续4天。在P32和P90时，将大鼠置于自我给药室，测试其获得可卡因（0.2或0.5 mg/kg/注射）5天。由于这些变量没有显著的影响，数据在可卡因剂量和性别之间被分解。与生理盐水对照组或成年大鼠相比，经尼古丁预处理的青春期大鼠表现出明显更大的可卡因强化反应（p < 0.01）。这种药物预处理效果并不适用于所有奖励，因为尼古丁并没有增加青少年对蔗糖颗粒的反应。这些发现提供了证据，证明青少年的大脑特别容易受到尼古丁对随后的药物奖励的影响。(c) 2006爱思唯尔公司版权所有。
Adolescence is a critical period for the initiation of drug use, starting with tobacco and alcohol and progressing to marijuana and other illicit drugs. These findings have led to the suggestion that tobacco and alcohol are 'gateway' drugs that sensitize maturing reward pathways to the effects of illicit substances such as cocaine. To test this hypothesis, we have examined whether low-dose nicotine pretreatment alters acquisition of cocaine self-administration in adolescents more than in adults. Male and female Sprague-Dawley rats, aged postnatal day (P) 28 or P86, were given two daily intravenous injections of nicotine (0.03 mg/kg/0.1 ml) or saline for 4 days. At P32 and P90, rats were placed in self-administration chambers and tested for acquisition of cocaine (0.2 or 0.5 mg/kg/inj) for 5 days. Data were collapsed across cocaine dose and sex since there was no significant effect of these variables. Adolescent rats pretreated with nicotine exhibited significantly greater cocaine-reinforced responding as compared to saline controls or adults (p < 0.01). This drug pretreatment effect did not generalize to all rewards, since nicotine did not increase responding for sucrose pellets in adolescents. These findings provide evidence that the adolescent brain is uniquely vulnerable to the effects of nicotine on subsequent drug reward. (c) 2006 Elsevier Inc. All rights reserved.