Prior chronic nicotine impairs cued fear extinction but enhances contextual fear conditioning in rats
Prior chronic nicotine impairs cued fear extinction but enhances contextual fear conditioning in rats
复制标题
先前的慢性尼古丁会损害大鼠的暗示恐惧消退，但会增强情境恐惧条件反射
DOI：
10.1016/j.neuroscience.2008.03.005
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发表时间：
2008-06-02
期刊：
影响因子：
3.3
通讯作者：
Li, Z.
中科院分区：
文献类型：
--
作者：
Tian, S.;Gao, J.;Li, Z.
临床观察表明，吸烟与精神疾病（包括焦虑症）之间的高共病率存在联系。然而，人们对尼古丁依赖发展为焦虑症的神经机制知之甚少。一般认为，恐惧消退的缺陷会导致焦虑症。本研究的目的是探讨慢性尼古丁对大鼠恐惧消退的影响。大鼠皮下给药。尼古丁每天两次，持续14天。在最后一次注射后两周，大鼠接受线索或背景恐惧条件反射。在条件化后24小时和48小时，大鼠分别接受消退训练期和消退测试期。在训练的所有阶段评估冻结百分比。在线索任务中，先前的慢性尼古丁不影响获得的恐惧反应或会话内的恐惧消退，但损害会话之间的恐惧消退。在情境任务中，相同的尼古丁治疗时间表不影响恐惧反应的获得或会话内和会话之间的恐惧消退，但增强了恐惧条件反射的保留。这种先前的慢性尼古丁诱导的线索恐惧消退和/或增强的恐惧背景的缺陷可能是一个关键的组成部分，有助于从尼古丁依赖性进展到焦虑症。(C)2008由Elsevier Ltd代表IBRO出版。
Clinical observations have shown a link for the high comorbid rate between smoking and psychiatric disorders, including anxiety disorders. However, little is known about the neural mechanism underlying the progression from nicotine dependence to an anxiety disorder. A deficit in fear extinction in general is considered to contribute to anxiety disorders. The aim of the present study is to investigate the effects of chronic nicotine on fear extinction in rats. Rats were administrated s.c. nicotine twice per day for 14 days. Two weeks after the last injection rats received a cued or contextual fear conditioning session. Twenty-four hours and 48 h after conditioning, rats received an extinction training session and an extinction test session, respectively. Percent freezing was assessed during all phases of training. In the cued task, prior chronic nicotine did not affect the acquisition of fear response or the within-session fear extinction, but impaired the between-session fear extinction. In the contextual task, the same nicotine treatment schedule did not affect the acquisition of fear response or the within- and between-session fear extinction, but enhanced the retention of fear conditioning. This prior chronic nicotine-induced deficit in cued fear extinction and/or enhanced fear to context may be one of the critical components that contribute to the progression from nicotine dependence to an anxiety disorder. (C) 2008 Published by Elsevier Ltd on behalf of IBRO.