慢性复合性应激对大鼠学习和记忆影响及海马中CaMKⅡ CaMmRNA和CREBmRNA水平的变化  

CHANGES OF LEARNING,MEMORY AND LEVELS OF CAMKⅡ,CAMmRNA,CREBmRNA IN THE HIPPOCAMPUS OF CHRONIC MULTIPLE-STRESSED RATS

作　　者：孙臣友[1] 戚双双[2] 孙淑红[1] 周鹏[1] 崔怀瑞[1] 刘能保[3] 

机构地区：[1]温州医学院解剖学教研室,温州325035 [2]温州医学院第二附属医院药剂科,温州325027 [3]华中科技大学同济医学院组织学胚胎学教研室,武汉430030

出　　处：《解剖学报》2008年第4期475-480,共6页Acta Anatomica Sinica

基　　金：国家自然科学基金资助项目(30270446);浙江省医药卫生科技计划资助项目(2006B107);温州市科技计划资助项目(Y20060085)

摘　　要：目的探讨慢性复合应激对大鼠学习与记忆的作用,以及Ca2+/钙调蛋白依赖性蛋白激酶Ⅱ(CaMKⅡ)、钙调蛋白(CaM)mRNA、环腺苷酸反应元件结合蛋白(CREB)mRNA水平的变化及其在学习和记忆中的作用。方法Wistar大鼠被随机分为慢性复合应激组(16只)和对照组(16只)。慢性复合应激组动物给予6周的慢性复合应激刺激,制备慢性复合应激模型;Morris水迷宫和Y迷宫测试大鼠空间学习和记忆的行为表现;免疫组织化学、Western blotting和RT-PCR检测大鼠海马CaMKⅡ、CaM mRNA和CREB mRNA水平的变化;观察分析CaMKⅡ在海马CA1和CA3区的分布和表达;电镜观察海马CA3区突触间隙的宽度和突触后致密物质(PSD)的厚度的变化。结果慢性复合应激6周后,应激组大鼠的学习与记忆能力均高于对照组(P<0.05,P<0.01);应激组海马CA3区突触间隙的宽度为5.0580±1.4216,PSD的厚度为20.9547±2.5693。与对照组相比,海马CA1和CA3区辐射层和始层CaMKⅡ的免疫染色明显增强,特别是始层;CaMKⅡ、CaM mRNA及CREB mRNA水平均明显增高(P<0.05,P<0.01)。结论慢性复合性应激后,大鼠的学习与记忆能力增强;海马CaMKⅡ、CaM mRNA和CREB mRNA水平增加可能是参与了慢性复合应激性学习记忆增强的机制。Objective To investigate the effects of chronic multiple-stress on learning and memory and on the levels of calcium/calmodulin-dependent protein kinase Ⅱ （CaMK Ⅱ ）, calmodulin （CAM） mRNA, and cAMP-response element binding protein （CREB） mRNA in the hippocampus of rats and possible mechanisms. Methods The Wistar rats were divided randomly into stressed （ n = 16） and control groups （ n = 16）. The stressed group was given chronic multiple-stress for 6 weeks to prepare the chronic multiple-stressed model. The rats＇ performance of spatial learning and memory was tested by Morris water maze （MWM） and Y-maze. The expressions of CaMK Ⅱ , CaM mRNA and CREB mRNA in hippocampus of rats＇ were detected by immunohistochemistry, Western blotting and RT-PCR respectively. The width of synaptic cleft and the thickness of post-synaptic densities （PSD） were observed in the hippocampal CA3 region of rats under electron microscopy. Results After the exposure to chronic multiple-stress for 6 weeks, the ability of learning and memory of the stressed group was higher than that of the control group （ P 〈 0.05, P 〈 0.01 ）. The width of synaptic cleft was 5. 0580 ± 1.4216 and the thickness of PSD was 20. 9547 ± 2. 5693 in the hippocampal CA3 of stressed rats. Compared with the control group, the CaMK Ⅱ immunostaining of stressed animals was stronger in the stratum radiatum and oriens of hippocampal CA1 and CA3, especially in the stratum oriens. The expressions of CaMK H , CaM mRNA, and CREB mRNA in the hippocampus of the stressed group was significantly higher （P 〈 0.05, P 〈 0.01）. Conclusion The capacity of learning and memory was enhanced following chronic multiple-stress. The increase in the levels of hippocampal CaMK H , CaM mRNA, and CREB mRNA revealed that they might have participated in the enhancing effect of chronic multiple-stress on learning and memory.

关 键 词：慢性复合性应激 学习和记忆 海马 Ca^2+/钙调蛋白依赖性蛋白激酶Ⅱ 钙调蛋白mRNA 环腺苷酸反应元件结合蛋白mRNA 迷宫 大鼠 

分 类 号：R322.81[医药卫生—人体解剖和组织胚胎学]