快速老化痴呆模型小鼠SAMP8学习记忆能力的增龄性变化

Age-related Changes in Learning and Memory in the Senescence Accelerated Dementia Mouse SAMP8

目的对快速老化痴呆模型小鼠SAMP8学习记忆能力的增龄性变化进行较系统的研究,为利用该模型进行其他研究提供实验依据。方法此实验选用1、4、8、12月龄的快速老化痴呆模型小鼠SAMP8,与同龄的正常老化小鼠SAMR1作对照,从老化度评分、避暗实验、Morris水迷宫实验和自主活动实验等方面观察了SAMP8小鼠学习记忆能力的增龄性变化。结果与对照组SAMR1相比,SAMP8小鼠随月龄增加老化度评分呈增高趋势,在8、12月龄的老化度评分值显著高于同龄对照组(P<0.05);避暗实验中,8、12月龄的SAMP8小鼠在电击24h后进入暗箱的潜伏期比同龄SAMR1小鼠显著缩短(P<0.05);Morris水迷宫实验中,1、4月龄SAMP8小鼠找到暗台的潜伏时间与同龄SAMR1小鼠相比差异无显著性,而8、12月龄SAMP8小鼠与同龄对照组相比,潜伏时间显著延长(P<0.05);从自主活动实验看,1、4、8月龄SAMP8小鼠单位时间内自主活动次数与同龄SAMR1小鼠相比无显著变化,而12月龄SAMP8小鼠与同龄对照组相比单位时间内自主活动次数显著减少(P<0.05)。结论SAMP8小鼠随月龄增长学习记忆能力逐渐减退;与同龄对照组相比,8、12月龄SAMP8小鼠出现明显衰老特征,表现出学习记忆能力明显低下,故可作为老化痴呆的动物模型用于痴呆有关研究。

Objective Age-related changes in learning and memory were observed in the senescencea ccelerated mouse SAMP8 as a dementia animal model. Methods The ability of learning and memory in SAMP8 mice in 1,4,8 and 12 months were studied by grading score system for aging, passive avoidance response, Morris water task and spontaneous motor activity. Normal aging control mouse SAMR1 (senescence-resistant substrain) was used. Results Compared with SAMR1 mice, SAMP8 mice showed an age-related significant increase (P<0.05) in grading score for aging; and an age-related significant decrease (P<0.05) in the (latency) time in passive avoidance response; and an age-related significant increase (P<0.05) in the latency time in Morris water task. In the spontaneous motor activity tests, only 12-month SAMP8 mice showed an significant decrease (P<0.05) in the the spontaneous motor activity compared with 12-month SAMR1 mice. Conclusions The results suggested that SAMP8 mouse showed deficits in learning ability, SAMP8 mouse was useful for investigating the mechanism of brain-aging and a pertinent animal model of senile dementia.