孕期丰富环境对子代小鼠学习记忆功能的影响

Effect of prenatal enriched environment on learning and memory ability in mice offspring

目的探讨雌性小鼠孕期给予丰富环境刺激对子代新生小鼠空间学习记忆能力的影响。方法选择SPF级C57BL/6受孕雌鼠24只随机分为丰富环境组和标准环境组,在整个孕期分别给予丰富环境、普通环境的刺激直至分娩为止。两组小鼠出生后均移至普通环境饲养,在出生后的1个月及2个月时分别对子代小鼠进行水迷宫行为学检测、海马区新生神经元的免疫荧光检测。结果在1月龄的子代小鼠中,定位航行实验显示丰富环境组比普通环境组小鼠的平均逃避潜伏期时间明显缩短(P<0.05),而空间探索实验显示丰富环境组平台象限游泳距离百分比和穿台次数均高于普通环境组(P<0.05)。在海马CA1区和齿状回,丰富环境组神经元前体细胞标记物微管相关蛋白Doublecortin(DCX)阳性神经细胞数目较普通环境组明显增多(P<0.05)。而在2月龄的子代小鼠检测中,两组小鼠在上述指标均无明显统计学差异。结论在母鼠妊娠期间给予丰富环境刺激可以一过性提高子代小鼠的学习记忆能力以及神经发生发育。

Objective To explore the effect of prenatal Enriched Environment on spatial learning and memory ability in mice offspring. Method 24 SPF successful pregnancy C57BL/6 mice were randomly divided into 2 groups, 12 per group, the enriched environment group and the standard environment group. Their offspring were both raised in the normal environment postnatally. Spatial learning was evaluated by Morris water maze test and then the brain was taken for BrdU and DCX double staining. We detected index at their first and second month after the birth separately. Results The result from the spatial discriminative learning ability ： in the first month of the offspring, enriched environment group took much less time to find the platform on days 4-5 （P〈0.05） ,though there was no significantly difference over days 1-3. The mice of enriched environment group spent a significantly larger percentage of time in the target quadrant （TQ） than the normal environment group （P〈0.05）. In the second month, the difference was no significance in statistics between two groups both in Cue navigation test and Probe trail test. The result of immunohistochemical method： Newly formed maturate neurons in mouse enriched environment group was significantly more than the normal environment group（P〈0.05 ） in the first month after birth, nevertheless, there was nearly no difference between two groups in the second month. Conclusion En- riched Environment in pregnancy transiently increase postnatal learning and memory ability in the offspring.