海马注射Aβ_(1～40)诱导大鼠记忆减退及其脑内细胞周期蛋白A的异常表达

目的 :探讨 β -淀粉样蛋白 (β -amyloid ,Aβ1～ 40 )毒性作用能否导致成年大鼠脑内神经元表达细胞周期相关蛋白 ,以及细胞周期相关蛋白表达与神经损伤及记忆减退之间的关系。方法 :运用行为学测试、免疫组化、积分光密度分析等手段对Aβ1～ 40 多肽片段双侧海马注射的大鼠脑进行研究。结果 :Aβ1～ 40 注射 7d后大鼠记忆明显减退 (P <0 .0 5 ) ,且大鼠脑内细胞周期蛋白A(cyclinA)在神经元异常表达 ,但术后 2 1d时cyclinA的表达有所降低。结论 :Aβ1～ 40 可导致成年大鼠脑神经元表达细胞周期相关蛋白 ,大鼠脑内神经元细胞周期相关蛋白的异常表达与阿尔茨海默病 (Alzheimer’sdisease,AD)相关病理改变存在关联

Aberrant neuronal expression of cyclin A in the rat brain after injection of Aβ1～40 into the hippocampi

Objective To investigate whether the toxicity of β-amyloid protein (Aβ_(1～40)) induces mitotic protein cyclin A expression in adult rat brain. Methods Immunohistochemical and integral optical density analysis method was used to detect the expression of cyclin A in adult rat brains after injecting Aβ_(1～40) into the hippocampi. Results The aberrantly expression of cyclin A was detected at 7 d after operation in Aβ_(1～40) injection into rat brains,but the level of cyclin A decreased at 21d. Conclusion Aβ_(1～40) causes cyclin A expression in adult rat brain neurons.The aberrant neuronal expression of cyclin A in adult rat brain may be related to Alzheimer’s disease (AD) pathological changes.