慢性应激对大鼠空间学习记忆及海马和前脑皮层突触体膜流动性的影响  

Chronic Stress Impairs Learning and Memory and Changes Frontal and Hippocampal Synaptosomal Membrane Fluidity in Rats

作　　者：李亚[1] 孔宏[1] 宋倩[1] 蔡景霞[2] 

机构地区：[1]曲阜师范大学生命科学学院,山东曲阜273165 [2]中国科学院昆明动物研究所脑与行为研究室,昆明650223

出　　处：《心理学报》2010年第2期235-240,共6页Acta Psychologica Sinica

基　　金：国家自然科学基金项目(30070251);曲阜师范大学"十一五"计划省级重点建设项目;博士科研项目(Bsqd200515)

摘　　要：慢性应激对学习记忆功能的影响是神经科学的热点问题,在脑内,海马和前额叶是与学习记忆功能密切相关的重要脑区,也是应激易累及损伤的主要靶区。膜流动性的改变在神经细胞功能活动中起重要作用。为探讨慢性应激对大鼠空间学习记忆功能的影响及前脑皮层和海马突触体膜流动性的作用。采用多因素慢性应激动物模型,通过开场试验和Morris水迷宫测试大鼠行为及空间学习记忆能力;并且测定大鼠前脑皮层和海马突触体膜流动性和突触体内游离Ca2+浓度的变化。研究结果显示,与对照组相比,应激组大鼠在应激后即刻,在新异环境中的自发活动和探究行为显著降低(p<0.05,p<0.01),空间学习记忆能力明显下降(p<0.05,p<0.01);并且应激组大鼠前脑皮层和海马突触体膜流动性显著降低(p<0.05,p<0.01);而突触体内游离Ca2+浓度的显著增加(p<0.05,p<0.01)。停止应激后一周,应激大鼠的各项指标有所恢复,但仍未达到正常水平。研究结果提示,慢性应激引起大鼠明显的开场行为改变和空间学习记忆功能障碍,这些变化可能与突触体膜流动性和突触体内游离Ca2+浓度的变化密切相关。The effect of chronic stress on learning and memory functions has been one of hot topics in neuroscience.Hippocampus （HP） and frontal cortex （FC） are key brain regions mediating learning and memory,as well as potential targets of stress reactions.Reduced membrane fluidity may represent an important mechanism underlying a variety of structural and functional alterations of the brain.The aim of the present study was to investigate the effects of chronic stress on spatial learning and memory,as well as membrane fluidity of frontal and hippocampal synaptosomes in rats.A 21-day chronic stress procedure with multiple stressors （footshock,noise,bondage,bondage plus thermal stimulus） was conducted.After that spontaneous behavior and spatial learning and memory performance were tested using open field and Morris water maze tasks.Frontal and hippocampal synaptosomal membrane fluidity and free calcium concentrations （[Ca2＋]i） were also examined.The results demonstrated that spontaneous locomotor activities and exploratory behaviors were significantly decreased in stressed animals.Their spatial learning and memory performance were significantly impaired as well.Furthermore,in chronic stressed animals,the frontal and hippocampal synaptosomal membrane fluidity were markedly reduced whereas the [Ca2＋]i were significantly increased as compared to control group.Current findings suggest that chronic stress results in behavioral changes and impairment of spatial learning and memory,which could be mediated by the changes of synaptosomal membrane fluidity and free calcium concentrations.

关 键 词：慢性应激 空间学习记忆 膜流动性 海马 前脑皮层 

分 类 号：B845[哲学宗教—心理学] Q427[生物学—神经生物学]