D-半乳糖致脑老化小鼠的物体识别能力障碍研究

Impairment of object recognition in aging model induced by D-galactose

目的应用物体识别方法研究D 半乳糖长期注射致脑老化小鼠模型的学习记忆能力 ,并比较物体识别方法与Morris水迷宫方法对该模型测试的灵敏性。方法C5 7BL/ 6小鼠 ,随机分成正常对照组、D 半乳糖低剂量组 (5 0mg/kg ,sc)、D 半乳糖高剂量组 (10 0mg/kg ,sc) ,连续造模 8周。以物体识别方法和Morris水迷宫方法测试各组动物的学习记忆能力。结果在物体识别测试中 ,D 半乳糖高剂量组分辨指数 (15 .71± 3 .94)较对照组 (4 5 .89± 7.41)减低具有非常显著性意义 (P <0 .0 0 1) ,低剂量分辨指数(2 4.69± 6.2 5 )与对照组的差异也存在显著性意义 (P <0 .0 5 )。在Morris水迷宫测试中 ,D 半乳糖高剂量组动物逃逸潜伏期比对照组延长有显著性意义 (P <0 .0 1) ;高剂量组在目标象限空间探索所停留时间与游泳距离比均较正常对照组减少有显著性意义 (P <0 .0 5 )。结论D 半乳糖可导致小鼠出现显著的物体识别能力障碍 ,用物体识别测试方法比Morris水迷宫方法更灵敏地反映该模型小鼠的学习记忆障碍。

Objective To study the object recognition impairment in D-galactose (D-gal) induced aging model with object recognition test (ORT), and compare the ORT and Morris water maze (MWM) in testing learning and memory in this model. Methods C57BL/6 mice divided into groups of control, D gal (50mg/kg) and D gal (100mg/kg). Each mouse was treated with vehicle or D gal (s.c.) once per day for 8 weeks. The ORT was used to test the object recognition preference and MWM for spatial learning and memory ability. ResultsFor ORT, D gal groups of both doses showed significantly less exploration time on new object (P<0.05); the discrimination index (DI) of high dose showed very significant lower DI (P<0.001), and low dose showed significant lower DI (P<0.05), compared with control group. During 4 day spatial learning and memory training in MWM, high dose D gal group showed significant longer escape latency (P<0.01); in the probe trial, mice of high dose group showed significant less time and distance in the target quadrant compared with control group. ConclusionMice of chronic subcutaneous D gal injection showed serious object recognition impairment, the object recognition test is more sensitive than Morris water maze in reflecting the learning and memory impairment in this model.