Effects of chronic stress of early tooth extraction on hippocampus in senescence-accelerated mice

这项评估是关于长期牙齿缺失是否会导致加速衰老小鼠(SAMP8)海马区功能和形态的变化。在Morris水迷宫学习和空间记忆实验中，成熟或老年长期牙齿缺失组小鼠的学习和空间记忆能力明显低于年龄匹配的对照组。3、成熟和老年长期牙齿缺失组大鼠海马神经元数量明显少于年龄匹配的对照组。而成熟或老年长期缺牙组大鼠海马CA1区或齿状回(DG)区的GFAP阳性细胞数与年龄匹配的对照组比较差异无统计学意义。4、成熟或老年长期缺牙组大鼠海马CA3区GFAP阳性细胞数明显高于年龄匹配的对照组。而成熟和老年小鼠海马区CA1和DG的表达无明显差异。5.成熟或老年长期牙齿缺失组小鼠海马DG区BrdU阳性细胞数明显高于年龄匹配的对照组。6.在海马区，注意到成熟或老年长期牙齿缺失组突触素的表达明显低于年龄匹配的对照组。

This evaluations were whether long-term tooth loss induces functional and morphologic changes in the hippocampus in senescence-accelerated mice(SAMP8). The teeth were extracted at an early age.The results were as follow.1, Plasma corticosterone concentration as a stressor was significantly higher in old or mature mice with long-term tooth loss groups than in the age-matched controls.2, In the Morris water maze learning and spatial memory trials was significantly slower in the mature or old long-term tooth loss groups compared with the age-matched controls.3, The number of hippocampal neurons was significantly reduced in the CA3 region of the hippocampus in the mature and old long-term tooth loss groups compared with their age-matched controls, but there was no significant difference in the CA1 or dentate gyrus(DG) region between the mature or old long-term tooth loss groups and their age-matched controls.4, The number of GFAP-positive cells was significantly higher in the CA3 region of the hippocampus in the mature or old long-term tooth loss groups compared with age-matched controls. However, no significant difference was observed in the CA1 or DG of the hippocampus in the mature or old mice.5, The number of BrdU-positive cells was significantly increased in the DG of the hippocampus in the mature or old long-term tooth loss groups compared with age-matched controls.6, In the hippocampus, note the significant decrease in synaptopysin expression in the mature or old long-term tooth loss groups compared with age-matched controls.The findings indicated that long-term tooth loss enhances the effects of aging on the hippocampus in mice.