摘要目的 观察牙齿缺失对小鼠空间学习记忆能力与海马结构的影响.方法 60只成年雄性小鼠随机分成牙齿缺失组和正常对照组.牙齿缺失组拔除左侧上下颌臼齿,正常对照组不予任何刺激.于麻醉和拔牙手术后2周采用Morris水迷宫系统测试各组小鼠的学习记忆能力,连续测试5 d,分析小鼠潜伏期、经过平台象限的次数(FPP)和停留时间(TAQ),之后用H-E和Nissl染色观察其海马结构神经元的变化.结果 牙齿缺失组小鼠4d平均逃避潜伏期[(46.5±3.8)s]显著低于对照组[(33.2±4.0)s],对照组小鼠目标象限停留时间[(19.7±6.5)s]明显高于牙齿缺失组[(11.4±5.2)s].高倍镜下观察,H-E和Nissl染色的海马组织切片均显示手术组较对照组的颗粒细胞数目少、排列稀疏.结论 牙齿缺失会对小鼠空间学习记忆能力以及海马结构造成一定损伤.

abstractsObjective To investigate the effect of missing molars on spatial learning and memory and hippocampa formation in mice. Methods 60 adult mail mice were randomly divided into unilateral molars extraction group and control group. The ability of spatial learning and memory of these mice were tested with the Moms water maze 2 weeks after anesthesia and operation of tooth extraction was done. The experiment lasted for five days. After 5 days, the avoiding latency, the frequency of passing the platform(FPP)and the stay time in the aim quadrant (TAQ)were determined in mice,and then the effect of the hippocampal formations were analysed on the slices stained with thionin-eosin(H-E)and Nissl of all experimental animals. Results The average latent period for four days for mice in missing molars group[(46.5±3.8)s]was obviously longer than control group[(33.2±4.0)s],and the mice in control group had significantly longer stay time in the aim quadrant(P＜0.05).After staining with H-E and Nissl, there were few and sparse granulosa cells in the hippocampa formation of missing molars group under light microscope. Conclusion Missing molars will cause a certain damage on the ability of spatial learning and memory and the hippocampa formation of mice.