小胶质细胞清除对小鼠空间型学习与记忆的影响

EFFECT OF MICROGLIAL CELL ELIMINATION ON SPATIAL LEARNING AND MEMORY IN MICE

目的探讨细胞集落刺激因子1受体(CSF1R)抑制剂PLX5622对C57BL/6小鼠空间型学习与记忆的影响。方法16只健康雄性C57BL/6小鼠随机分为实验组和对照组,各8只。实验组小鼠连续2周投食含PLX5622的鼠粮,对照组小鼠投食等量的标准鼠粮。采用Morris水迷宫实验检测两组小鼠的空间型学习力与记忆力;应用荧光免疫组化法测定两组小鼠海马区域小胶质细胞的密度。结果水迷宫结果显示,与对照组相比,实验组小鼠在圆台所在象限探索的时长百分比明显下降(t=3.556,P<0.01),逃避潜伏期、穿越圆台次数、游泳速度差异无显著性(P>0.05)。荧光免疫组化结果显示,与对照组相比,实验组小鼠每平方毫米海马区域小胶质细胞的数量明显减少(t=11.430,P<0.01),成熟神经元数量两组比较差异无显著性(P>0.05)。结论海马区域小胶质细胞清除不影响小鼠空间学习与记忆获取,但削弱小鼠的空间型记忆力。

Objective To investigate the effect of the colony-stimulating factor 1 receptor inhibitor PLX5622 on the spatial learning and memory in C57BL/6 mice.Methods A total of 16 healthy male C57BL/6 mice were randomly divided into control group and experimental group,with 8 mice in each group.The mice in the experimental group were given PLX5622-based chow diet for 2 consecutive weeks,and those in the control group were given an equivalent amount of normal chow diet.Morris water maze test was conducted to evaluate the spatial learning and memory of the mice.Fluorescent immunohistochemistry was used to determine the density of microglial cells in the hippocampus of the mice.Results Morris water maze test showed that the searching time(%)for the platform in the target quadrant was significantly reduced in the experimental group compared with that in the control group(t=3.556,P<0.01),while the escape latency,number of platform crossings,and swimming speed were not significantly different between the two groups(P>0.05).Fluorescent immunohistochemistry showed that the number of microglial cells per square millimeter of the hippocampus was significantly reduced in the experimental group compared with that in the control group(t=11.430,P<0.01),while the number of mature neurons was not significantly different between the two groups(P>0.05).Conclusion Microglial cell elimination in the hippocampus has no significant effect on spatial learning and memory acquisition in mice,but it reduces the spatial memory of the mice.