中老年CD-1小鼠海马Staufen蛋白含量改变及其与认知功能减退的相关性研究

Changed Staufen level of hippocampus correlates with the impaired spatial learning and memory in the middle-aged CD-1 mice

探讨中老年CD-1小鼠海马Staufen(Stau)蛋白含量的改变及其与空间学习记忆功能减退之间的相关性。选取3月龄(青年)和15月龄(中老年)CD-1小鼠各10只(雌雄各半)。采用Morris水迷宫评估空间学习记忆能力,用免疫组织化学技术检测海马Stau蛋白的相对含量。结果发现,与3月龄小鼠相比,15月龄鼠在Morris水迷宫中学习期游泳路程显著延长(P<0.01),记忆期靶象限游泳路程百分比显著降低(P<0.05),且海马CA1区和CA3区Stau蛋白含量显著升高(P<0.05)。相关性分析显示,15月龄小鼠CA1区、CA3区Stau蛋白含量与学习期游泳路程呈正相关(P<0.05),CA3区Stau蛋白含量与记忆期靶象限路程百分比呈负相关(P<0.05)。以上结果提示中老年CD-1小鼠海马Stau蛋白含量呈亚区特异性增加,且可能与海马相关性空间学习记忆的损害有关。

To investigate whether the changed level of Staufen(Stau) protein exists in the hippocampus of middle-aged CD-1 mice, and if this is case, whether it is correlated with impairment of spatial learning and memory, 3-month(young) and 15-month(middle-aged) CD-1 mice were used(5 males and 5 females per group) to evaluate the ability of spatial learning and memory using Morris water maze test, and the expression of Stau protein was examined using immunohistochemical method. The results showed that compared to the 3-month mice,the 15-month mice had significantly longer swimming distance during the learning phase(P<0.01) and lower percentage of distance in the target quadrant during the memory phase(P<0.05) in the Morris water maze. The15-month mice showed significantly higher level of Stau protein in the hippocampal CA1 and CA3 subregions(P<0.05). Correlation analysis indicated that the Stau level in the CA1 and CA3 negatively correlated with the learning swimming distance(P<0.05), while the protein level in the CA3 positively correlated with the memory percentage of distance in the target quadrant in the 15-month mice(P<0.05). These results suggested that the Stau protein content in hippocampus increased in a subareas-dependent manner in the middle-aged CD-1 mice, and this increment was associated with the impaired spatial learning and memory.