应用水迷宫测试糖尿病大鼠空间记忆能力变化的研究

Effect of diabetes on spatial memory ability in rats using Morris water maze

目的 研究大鼠患糖尿病后,空间记忆能力和空间关联记忆能力受到的影响.方法 将70只SD大鼠（体质量180 g±20 g）随机分成3组,对照组、1型糖尿病组和2型糖尿病组.采用STZ一次性腹腔注射和联合高脂饲料喂养的方法分别制备1型和2型糖尿病大鼠模型,检测血糖水平.在造模成功的1个月和3个月后,分别进行水迷宫实验,包括4 d的定位航行和1 d的空间探索实验.结果 在糖尿病造模成功的1个月后,大鼠没有发生明显的空间记忆能力或空间关联记忆能力障碍.造模3个月后,在定位航行实验中,2组糖尿病大鼠的逃避潜伏期都比对照组时间长,具有统计学差异（P＜0.05）.实验第2天开始,对照组逃避潜伏期的下降趋势明显,而糖尿病组下降缓慢.1型和2型糖尿病组之间的逃避潜伏期没有显著差异（P＞0.05）.造模3个月后,在空间探索实验中,从训练过的Ⅰ象限入水时,2个糖尿病模型组平台象限游泳时间短,第1环点数和总得分等参数低,与对照组的差异都具有显著意义（P＜0.05）,2型糖尿病组的参数值比1型糖尿病组稍低.从未训练的Ⅳ象限入水时,糖尿病模型组的参数值也均低于正常对照组,具有统计学差异（P＜0.05）,且1型糖尿病组的总得分比2型糖尿病组更低一些.结论 1型或2型的糖尿病大鼠会发生空间记忆能力和空间关联记忆能力的下降.本实验中2型糖尿病组的空间记忆能力比1型糖尿病组受到了更明显的影响,而1型糖尿病组的空间关联记忆能力受到的影响比2型糖尿病组更大.

Objective To study the effect of diabetes on spatial memory ability and spatial associative memory ability in rats. Methods 70 SD rats（ 180±20 g） were randomly divided into 3 groups： control group,type1 diabetes group and type2 diabetes group. Type1 and type2 diabetic rat models were set up by streptozocin （STZ） intraperitoneal injection and high fat forage raise. The blood glucose was determined. After rat diabetic model established 1 month and 3 months, respectively, the Morris water maze experiments were implemented,including 4 days＇ place swimming and 1 day＇s space exploration. Results After 1 month, diabetic rats＇ spatial memory ability and spatial associative memory ability were not affected. After 3 months, in place swimming test,the escape latency of two diabetic rat groups was obviously longer than that of the control group （P〈0.05）. From the second day of the experiment, escape latency of the control descended sharply, while that of the diabetic group descended slowly. There was no difference between type 1 and type2 diabetic groups in escape latency （P〉0.05）. After 3 months, in the space exploration test, when rats were put into the maze from I quadrant which already trained, swimming time in the platform quadrant was shorter, the other parameter scores were lower of the two diabetic model groups, contrast to the control group （P〈0.05）. The parameter scores of type2 diabetic group were lower slightly than type1 diabetic group. When rats were put into the maze from IV quadrant for which never trained, the parameter scores of two diabetic groups were lower than that of the control group （P〈0.05） and the total score of type 1 group was lower than that of type2 group. Conclusion The spatial memory ability and spatial associative memory ability of type 1 and type2 diabetic rats descended. In the experiment, the spatial memory ability of type2 diabetic rats was more significantly affected than that of type1 diabetic rats. By contrast,type 1 diabetic rats＇ spatial associative memory ability descended greatly than that of type2 diabetic rats.