Adolescent nicotine expo-sure produces less affective measures of withdrawal relative to adult nicotine exposure in male rats
Adolescent nicotine expo-sure produces less affective measures of withdrawal relative to adult nicotine exposure in male rats
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DOI：
10.1016/j.ntt.2006.11.003
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发表时间：
2007-01-01
影响因子：
2.9
通讯作者：
Tejeda, Hugo A.
中科院分区：
文献类型：
--
作者：
O'Dell, Laura E.;Torres, Oscar V.;Tejeda, Hugo A.
在青春期开始吸烟的个体中，尼古丁成瘾的脆弱性显著增加;然而，这种现象的潜在机制仍不清楚。本研究采用条件性位置厌恶范式，考察了尼古丁戒断对青少年（PND 27-42）和成年（PND 60-75）大鼠的激励作用。雄性Wistar大鼠进行了测试，以确定它们最初对我们的条件反射装置的两个不同隔室中的任何一个的偏好。然后在大鼠皮下植入（sc）泵，产生等同的尼古丁血浆水平，持续14天。在尼古丁暴露的最后8天进行调节。大鼠接受烟碱拮抗剂美加明（1.5或3.0 mg/kg，sc）在其最初首选的隔室中沉淀戒断，并在隔天在其非首选隔室中接受盐水。调节后，重新测试大鼠对每个隔室的偏好。随后的研究进行了另一个厌恶刺激，氯化锂（LiCl）产生的学习位置厌恶检查潜在的发展差异。大鼠接受氯化锂（0，10，30，或100毫克/公斤，sc）在他们最初的首选侧使用类似的空调程序。成年人表现出强烈的尼古丁戒断产生的地方厌恶。这种影响在青春期大鼠中较低，即使在一组在条件反射前接受额外7天尼古丁暴露的年轻大鼠中也是如此。这种发展差异是特定的尼古丁戒断，因为有没有青少年和成人之间的差异，在学习地方厌恶与氯化锂。我们的研究结果表明，尼古丁戒断的影响减少构成了青春期尼古丁依赖脆弱性增加的有力依据。(c)2006年爱思唯尔公司All rights reserved.
Vulnerability to nicotine addiction is significantly increased in individuals who begin smoking during adolescence; however, the underlying mechanisms of this phenomenon remain unclear. This study examined the motivational effects of nicotine withdrawal in adolescent (PND 27-42) and adult (PND 60-75) rats using the conditioned place aversion paradigm. Male Wistar rats were tested for their initial preference for either of two distinct compartments of our conditioning apparatus. Rats were then implanted with subcutaneous (sc) pumps that produce equivalent blood plasma levels of nicotine for 14 days. Conditioning was conducted over the last 8 days of nicotine exposure. Rats received the nicotinic antagonist mecamylamine (1.5 or 3.0 mg/kg, sc) to precipitate withdrawal in their initially preferred compartment, and on alternate days they received saline in their non-preferred compartment. Following conditioning, rats were re-tested for their preference for each compartment. A subsequent study was conducted to examine potential developmental differences in learning place aversion produced by another aversive stimulus, lithium chloride (LiCl). Rats received LiCl (0, 10, 30, or 100 mg/kg, sc) in their initially preferred side using similar conditioning procedures. Adults displayed robust place aversion produced by nicotine withdrawal. This effect was lower in adolescent rats even in a group of young rats that received 7 additional days of nicotine exposure prior to conditioning. This developmental difference was specific to nicotine withdrawal since there were no differences between adolescents and adults in learning place aversion with LiCl. Our findings demonstrating reduced effects of nicotine withdrawal constitute a powerful basis for the increased vulnerability to nicotine dependence during adolescence. (c) 2006 Elsevier Inc. All rights reserved.