亚甲蓝对APP/PS1小鼠海马CA1区树突棘密度的保护作用

Protective effect of methylene blue on dendritic spines density in hippocampal CA1 of APP/PS1 mice

目的探讨亚甲蓝(MB)对APP/PS1转基因小鼠海马CA1区树突棘密度改变及学习记忆能力改善的影响。方法 APP/PS1小鼠及相同品系的3月龄野生小鼠,随机分为3组,每组10只:正常对照组,为野生小鼠。模型组,为APP/PS1小鼠;治疗组,3月龄的APP/PS1小鼠口服亚甲蓝25 mg·kg-1·d-1;连续用药4个月。待3组小鼠均为7月龄时,跳台实验测试3组小鼠的学习记忆能力;高尔基染色观察各组海马CA1区树突棘密度的变化。结果亚甲蓝治疗组小鼠跳台试验错误次数减少,小鼠跳台试验的潜伏期明显延长(P<0.01);治疗组与模型组相比海马CA1区树突棘密度明显增加(P<0.01),治疗组与对照组无统计学差异(P>0.05)。结论亚甲蓝可能是通过增加海马CA1区树突棘密度来改善APP/PS1小鼠的学习记忆能力。

Objective To investigate the effect of methylene blue （MB） on the ability of learning and memorizing and figure out the density of dendritic spine in hippocampal CA1 area of APP/PS1 transgenic mice. Methods 3-month-old APP/PS1 mice and wide type （WT） mice were divided into MB treated （treated with MB 25 mg .kg-1 .d-1, P. o. ）, model （without MB treatment）, and normal con- trol groups （WT mice）. The ability of learning and memorizing were assessed by step-down avoidance test 4 months later. The density of dendritic spine was observed by Golgi staining. Results Step-down avoidance test showed a decrease in the number of errors and a prolonga- tion in latency （P 〈 0. 01 ） after MB treatment. Compared with model group, the density of dendritic spine in MB-treated group was signifi- cantly increased. There was no statistical difference between model and MB-treated groups （P 〈 0. 05）. Conclusions MB could improve the ability of learning and memorizing by increasing the density of dendritic spine.