The expression of c-Fos and colocalisation of c-Fos and glucocorticoid receptors in brain structures of low and high anxiety rats subjected to extinction trials and re-learning of a conditioned fear response
The expression of c-Fos and colocalisation of c-Fos and glucocorticoid receptors in brain structures of low and high anxiety rats subjected to extinction trials and re-learning of a conditioned fear response
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DOI：
10.1016/j.nlm.2009.07.002
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发表时间：
2009-11-01
影响因子：
2.7
通讯作者：
Plaznik, Adam
中科院分区：
文献类型：
--
作者：
Lehner, Malgorzata;Wislowska-Stanek, Aleksandra;Plaznik, Adam
我们设计了一个动物模型来研究个体对厌恶刺激反应的不同机制。我们使用情境恐惧测试中的大鼠冻结反应作为区分变量：低反应者(LR)被定义为冻结反应持续时间比平均值低一个标准错误或更多的大鼠，高反应者(HR)被定义为冻结反应持续时间比平均值高一个标准错误或更多的大鼠。我们试图确定在接受条件恐惧训练、两次消退训练和重新学习条件恐惧的HR和LR大鼠中，c-Fos和糖皮质激素受体免疫反应(GR-IR)的共存情况。我们发现，与对照组和LR组相比，在两个消退过程中(16天)，HR组动物的条件性恐惧明显减少。在重新学习情境恐惧后，LR组大鼠大脑皮质M2区和前缘区(c-Fos)表现出更高的活性，M2和内侧眶皮质中c-Fos和GR-ir共同表达的细胞数量增加。与LR大鼠相比，HR大鼠杏仁基底外侧核c-Fos、GR-ir和c-Fos/GR-ir共定位神经元表达增加，齿状回c-Fos和GR-ir表达增强。我们的数据表明，HR动物在重新学习情境恐惧后，与情境相关的行为的恢复伴随着海马体DG区c-Fos表达和GRs-ir的选择性增加。(C)2009 Elsevier Inc.保留所有权利。
We designed an animal model to examine the mechanisms of differences in individual responses to aversive stimuli. We used the rat freezing response in the context fear test as a discriminating variable: low responders (LR) were defined as rats with a duration of freezing response one standard error or more below the mean value, and high responders (HR) were defined as rats with a duration of freezing response one standard error or more above the mean value. We sought to determine the colocalisation of c-Fos and glucocorticoid receptors-immunoreactivity (GR-ir) in HR and LR rats subjected to conditioned fear training, two extinction sessions and re-learning of a conditioned fear. We found that HR animals showed a marked decrease in conditioned fear in the course of two extinction sessions (16 days) in comparison with the control and LR groups. The LR group exhibited higher activity in the cortical M2 and prelimbic areas (c-Fos) and had an increased number of cells co-expressing c-Fos and GR-ir in the M2 and medial orbital cortex after re-learning a contextual fear. HR rats showed increased expression of c-Fos, GR-ir and c-Fos/GR-ir colocalised neurons in the basolateral amygdala and enhanced c-Fos and GR-ir in the dentate gyrus (DG) in comparison with LR animals. Our data indicate that recovery of a contextrelated behaviour upon re-learning of contextual fear is accompanied in HR animals by a selective increase in c-Fos expression and GRs-ir in the DG area of the hippocampus. (C) 2009 Elsevier Inc. All rights reserved.