摘要
目的研究慢性复合应激对成年雄性大鼠学习记忆功能和海马内蛋白激酶A(PKACβ)表达的影响。方法将成年雄性Wistar大鼠随机分为对照组和应激组,应激组动物每天交替暴露于复合应激原中达6周,并测定应激第3周和第6周时两组动物的血清皮质酮水平。应激结束后,用Morris水迷宫和Y迷宫测试大鼠空间学习记忆成绩,并采用免疫组织化学方法分析海马各亚区PKACβ的表达。结果应激组大鼠的血清皮质酮水平在第3周明显高于对照组,但在第6周两组差别不明显。在Morris水迷宫测试中,应激组动物寻找隐蔽平台的潜伏期明显短于对照组;Y迷宫测试中,应激组动物寻找安全区的正确率也显著高于对照组。应激组大鼠的海马CA1和CA3区PKACβ的表达水平较对照组明显上调,而齿状回(DG)内PKACβ的表达在两组中无明显差别。结论慢性复合应激可增强大鼠海马依赖的学习记忆能力,PKA可能参与了其增强机制。
Objective To examine the effect of chronic multiple stress on spatial learning and memory and the expression of the catalytic subunit-C_(β) of protein kinase A (PKA-C_(β)) in the hippocampus in adult rats.Methods The rats were randomly divided into control and stress groups. The rats in the stress group were irregularly and alternatively exposed to chronic multiple stress for 6 weeks. On the week 3 and week 6, the serum levels of corticosterone in both groups were measured. After the chronic multiple stress, all rats were tested for spatial learning and memory in Morris water maze and Y-maze. The expression of PKA-C_(β) in different subfields of the hippocampus was assayed by using immunohistochemical method.Results Compared with the control group, serum corticosterone levels in the stress group were increased significantly on the week 3, but no apparent difference between the two groups was observed on the week 6. After the chronic multiple stress, the latency to search the hidden platform in Morris water maze was markedly shortened in the stress group; and in the test of Y-maze, the correct rate of avoiding the electric shock was distinctively higher in the stress group. The expression of the PKA-C_(β) in hippocampal area CA1 and CA3 was significantly stronger in the stress group than that in the control group, but no difference was observed in DG area.Conclusion Chronic multiple stress may enhance the hippocampus-dependent learning and memory, and PKA may participate in the mechanism of the enhanced performance.
出处
《华中科技大学学报（医学版）》
CAS
CSCD
北大核心
2005年第3期257-261,共5页
Acta Medicinae Universitatis Scientiae et Technologiae Huazhong
基金
国家自然科学基金资助项目(No.30270446)
关键词
慢性复合应激
学习与记忆
蛋白激酶A
皮质酮
海马
chronic stress
learning and memory
protein kinase A
corticosterone
hippocampus
