Differential behavioral and neuroendocrine effects of repeated nicotine in adolescent and adult rats
Differential behavioral and neuroendocrine effects of repeated nicotine in adolescent and adult rats
复制标题
DOI：
10.1016/j.pbb.2004.12.007
复制
发表时间：
2005-03-01
影响因子：
3.6
通讯作者：
Planeta, CS
中科院分区：
文献类型：
--
作者：
Cruz, FC;DeLucia, R;Planeta, CS
尽管青少年中烟草滥用的发生率很高，但尼古丁成瘾的神经生物学主要在成年动物中进行研究。对成年大鼠重复施用这种药物会引起行为过敏。通过药物诱导的 ACTH 和皮质酮增加来测量尼古丁激活成年大鼠的 HPA 轴。行为敏感性和皮质酮都与毒瘾有关。我们研究了尼古丁诱导的行为敏化的表达，以及在青少年和成年动物中重复注射尼古丁后皮质酮水平的变化。青春期和成年大鼠每天一次皮下注射盐水或 0.4 mg/kg 尼古丁，持续 7 天。最后一次注射三天后，用盐水或尼古丁（0.4 mg/kg；皮下注射）对动物进行攻击。在活动笼中记录尼古丁引起的运动。在一部分青少年和成年大鼠中收集躯干血样，并通过放射免疫测定法测定血浆皮质酮水平。成年大鼠而非青少年大鼠表现出行为敏感性。用尼古丁进行预处理仅在成年动物中消除了该药物的皮质酮激活作用，表明在该年龄出现了耐受性。我们的研究结果提供了证据，表明反复接触尼古丁的青少年大鼠表现出与成年动物不同的行为和神经内分泌适应。 (c) 2004 Elsevier Inc. 保留所有权利。
Despite the high prevalence of tobacco abuse among adolescents, the neurobiology of nicotine addiction has been studied mainly in adult animals. Repeated administration of this drug to adult rats induces behavioral sensitization. Nicotine activates the HPA axis in adult rats as measured by drug-induced increases in ACTH and corticosterone. Both behavioral sensitization and corticosterone are implicated in drug addiction. We examined the expression of behavioral sensitization induced by nicotine as well as the changes in corticosterone levels after repeated injections of nicotine in adolescent and adult animals. Adolescent and adult rats received subcutaneous (s.c.) injections of saline or 0.4 mg/kg of nicotine once daily for 7 days. Three days after the last injection animals were challenged with saline or nicotine (0.4 mg/kg; s.c.). Nicotine-induced locomotion was recorded in an activity cage. Trunk blood samples were collected in a subset of adolescent and adult rats and plasma corticosterone levels were determined by radioimmunoassay. Adult, but not adolescent, rats expressed behavioral sensitization. Pretreatment with nicotine abolished corticosterone-activating effect of this drug only in adult animals, indicating the development of tolerance at this age. Our results provide evidence that adolescent rats exposed to repeated nicotine display behavioral and neuroendocrine adaptations distinct from that observed in adult animals. (c) 2004 Elsevier Inc. All rights reserved.