慢性复合应激对大鼠学习记忆功能及脑ERK表达活化的影响  

Effects of chronic multiple stress on learning and memory and the expression and phosphorylation of cerebral ERK of rats

作　　者：郑刚[1] 骆文静[1] 陈耀明[1] 刘明朝[1] 马金龙[1] 陈景元[1] 

机构地区：[1]第四军医大学军事预防医学系劳动与环境卫生学教研室,陕西西安710032

出　　处：《中国应用生理学杂志》2011年第1期33-36,共4页Chinese Journal of Applied Physiology

基　　金：国家科技支撑计划专项项目资助(2006BAI19B07)

摘　　要：目的:研究慢性复合应激对大鼠学习记忆的影响,以及大脑细胞外信号调节激酶(ERK)表达活化的变化,探讨慢性应激致学习记忆损害的分子机制。方法:采用低温暴露、足电击、白噪声、束缚、尾部悬吊、睡眠剥夺、水平震荡等刺激方式,建立慢性复合应激大鼠模型。Morris水迷宫实验观察应激对学习记忆的影响;放射免疫法检测血清皮质酮(CORT)含量;Western blot检测ERK的表达。结果:应激组大鼠水迷宫训练潜伏期较对照组延长,应激3周时有所恢复,但4周时大鼠的训练潜伏期再次显著延长(P<0.05)。同时应激组大鼠血清CORT水平增高,海马、前额皮质P-ERK水平降低(P<0.05),两者在应激3周时均出现短时恢复,但4周时再次下调。结论:海马、前额皮质ERK蛋白磷酸化水平的改变可能参与了慢性复合应激损害学习记忆的分子机制。Objective： To study the effect of chronic multiple stress on learning and memory,and the expression and activation of cerebral extracellular signal-regulated protein kinase（ERK）1/2 of rats in vivo.Methods： Ninety male SD rats were divided randomly into control group and stress group.Rats in stress group were stressed everyday by one of the seven stressors including cold exposure,foot shock,white noise,restraint,tail hung up,sleep deprivation,and level shake,and then the ability of learning and memory was determined by Morris water maze test.Serum corticosterone（CORT） level was determined by radioimmunoassay kit.Western blot was performed to determine the expression and phosphorylation of ERK in hippocampus and prefrontal cortex of the brain.Results： The escape latencies of stressed rats were substantially longer than those of the controls in the water maze test（P0.01） except a transient recovery at the end of the third week after the stress.The stress also resulted in significantly higher serum CORT level and decreased P-ERK level in hippocampus and prefrontal cortex（PFC）（P0.01）.Similarly,transient elevation of both CORT and P-ERK levels were observed at the end of the third week.Conclusion： Chronic multiple stress can lead to impaired learning and memory by decreasing the phosphorylation of ERK in the hippocampus and PFC.The partial recovery of learning and memory,CORT and P-ERK levels at the end of the third week may due to the adaptation of the rats to stressors.

关 键 词：应激 大鼠 学习记忆 细胞外信号调节激酶 

分 类 号：R338.6[医药卫生—人体生理学]