杏仁外侧核突触可塑性在抑郁症发病中的作用及机制研究

发布时间：2018-01-08 15:18

本文关键词：杏仁外侧核突触可塑性在抑郁症发病中的作用及机制研究　出处：《山东大学》2014年硕士论文　论文类型：学位论文

【摘要】：背景抑郁症是危害人类健康的常见神经精神性疾患,其病理机制迄今尚未彻底阐明。积累的证据显示抑郁症患者边缘系统的部分脑区出现结构、功能的改变,提示环境应激因素对边缘系统突触可塑性的影响在抑郁症的形成过程中起重要作用。杏仁核是边缘系统的重要结构,参与恐惧记忆的形成和消退。本研究在成功建立大鼠抑郁症模型的基础上,结合形态、分子生物学和行为学的技术手段研究了杏仁外侧核突触可塑性与抑郁行为形成的关系,同时探讨了姜黄素抗抑郁效应的机制。目的1.应用慢性不可预知性温和应激刺激(CUMS)建立大鼠抑郁症模型,研究抑郁行为和杏仁外侧核突触可塑性的关系。2.使用上述抑郁症模型探讨姜黄素的抗抑郁效应及其作用机制。方法将Wistar大鼠随机分为空白对昭、CUMS、姜黄素处理和溶剂对照四组。除空白对照组外,CUMS组,姜黄素处理组和溶剂对照组的动物均接受为期6周的慢性不可预知性温和应激刺激。姜黄素处理组在每次施予刺激前30分钟给予姜黄素腹腔注射,溶剂对照组给予姜黄素溶剂DMSO腹腔内注射。刺激完毕后对大鼠进行旷场实验、强迫游泳实验和糖水偏好实验等行为学测试。应用透射电子显微镜观察杏仁外侧核(LA)神经元超微结构。取杏仁外侧核组织进行免疫印迹和免疫荧光测定,观察BDNF、PSD-95和突触小泡蛋白(synaptophysin)表达水平的变化。用ERK阻断剂SL327预处理姜黄素组大鼠,观察对LA神经元及抑郁行为的影响,从而探讨姜黄素在抑郁症发生中的机制。结果(1)与空白对照组相比,CUMS组大鼠体重增加变缓,旷场实验中横向运动和纵向运动均明显减少,强迫游泳实验中静止时间显著增长而游泳时间变短,糖水偏好实验中糖水消耗量明显减少。(2)电镜结果显示CUMS组大鼠杏仁外侧核神经元出现核固缩和细胞器排列散乱等异常改变,而且出现突触数目减少以及突触前后膜变薄等突触结构变化。(3)免疫荧光和免疫印迹结果显示,与空白对照组相比,6周CUMS刺激导致LA部位的BDNF、PSD-95和synaptophysin的表达减少。(4)与CUMS组相比,姜黄素改善了大鼠的体重增长以及横向运动和纵向运动,同时减少了强迫游泳实验中的静止时间并增加了游泳时间,而且糖水消耗量也有明显增加。。免疫荧光和免疫印迹结果显示姜黄素治疗组LA部位BDNF、PSD-95和synaptophysin的表达水平均高于CUMS组动物。(5)另外,姜黄素的抗抑郁作用还伴随杏仁外侧核神经元磷酸化ERK1/2的表达水平的提高。结论1.CUMS诱导大鼠产生抑郁样行为并伴随杏仁外侧核神经元的突触可塑性改变。2.这一可塑性改变可能与CUMS下调ERK磷酸化水平,减少BDNF蛋白表达,从而影响了突触相关蛋白如PSD-95和synaptophysin的蛋白表达有关。3.姜黄素可通过ERK-BDNF调节神经突触可塑性变化,发挥其抗抑郁效应。
[Abstract]:Background depression is a common disease of nervous and mental harm to human health, the pathological mechanism has not been completely elucidated. The accumulation of evidence of brain structure in patients with depression of the limbic system, functional changes, suggesting the influence environmental stress factors on the plasticity of synaptic limbic system can play an important role in the formation process of depression in the amygdala. Is an important structure of the limbic system, the formation and extinction of fear memory. In the foundation of the establishment of rat model of depression in the success, combined with the form, the relationship between technology in molecular biology and behavior of the lateral amygdaloid nucleus of synaptic plasticity and depressive behavior formation, and discuss the mechanism of antidepressant effect of curcumin 1.. Application of chronic unpredictable mild stress (CUMS) to establish rat model of depression, depression and behavior of lateral amygdaloid nucleus synapses can be The plastic of the relation.2. to explore the use of the model of depression with antidepressant effect of curcumin and its mechanism. Methods: Wistar rats were randomly divided into the blank of Zhao, CUMS, curcumin and four solvent control group. Except the blank control group, CUMS group, curcumin treatment group and solvent control group animal were treated for a period of 6 weeks of chronic unpredictable mild stress. Curcumin administered 30 minutes before stimulation of curcumin intraperitoneal injection in each solvent control group received intraperitoneal injection of curcumin in DMSO solvent. After the stimulation of open field experiments on rats, the forced swimming test and sucrose preference test were studied by transmission electron testing. Microscope observation of lateral amygdaloid nucleus (LA) neurons. The ultrastructure of lateral amygdaloid nucleus tissue were observed by Western blot and immunofluorescence assay of BDNF, PSD-95, and synaptophysin (synaptophysin) The expression of inhibitor of SL327 pretreatment of curcumin. The rats in group ERK, observe the effect on LA neurons and depressive behavior, and to explore the mechanism of curcumin in occurrence of depression. Results (1) compared with the control group, CUMS group rats weight increased slowly, open field test and real transverse motion the vertical movement decreased immobility time during the forced swimming test increased significantly while swimming time, reduce the consumption of sucrose sucrose preference test. (2) electron microscope showed that CUMS rats lateral amygdaloid nucleus neurons karyopyknosis and organelles arranged scattered abnormal changes, and reduce the number of synapses and synaptic before and after the changes of membrane thinning of synaptic structure. (3) immunofluorescence and Western blot results showed that compared with the control group, 6 weeks stimulation with CUMS resulted in LA position of BDNF, PSD-95 and synaptophysin expression decreased (4) and CU. Compared with the MS group, curcumin improved the body weight gain of rats and the horizontal and vertical movement, and reduce the immobility time during the forced swimming test and the increase of the swimming time, and sugar consumption have increased significantly. Immunofluorescence and Western blotting showed Jiang Huang in treatment of BDNF group at the LA expression level of PSD-95 and synaptophysin the animal was higher than that in group CUMS (5). In addition, the antidepressant effects of curcumin with the expression level of lateral amygdaloid nucleus on the expression of phosphorylated ERK1/2 increased. Conclusion 1.CUMS induce depression like behavior and associated with synaptic plasticity with lateral amygdaloid nucleus neurons change.2. this plasticity may be associated with downregulation of CUMS ERK the phosphorylation level, decrease the expression of BDNF protein, thus affecting the synapse associated proteins such as PSD-95 and synaptophysin on the expression of.3. ERK-BDNF by curcumin can regulate the nerve The synaptic plasticity changes and plays its antidepressant effect.

【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R749.4

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