Arc基因与幼龄鼠和成年鼠记忆能力关系的研究

目的研究Arc基因与不同月龄大鼠记忆形成的关系,以探讨认知功能障碍的机制。方法应用Morris水迷宫对2月龄幼龄鼠和6月龄成年鼠进行定位航行训练和空间探索能力检测以判断其记忆形成情况,用RT-PCR检测海马Arc mRNA的表达量。结果幼龄鼠和成年鼠平均逃避潜伏期逐渐降低,第3d显著低于第1d（P〈0.05）,尤其是幼龄鼠,表明其学习、记忆能力强,但其平均逃避潜伏期仍高于成年鼠,虽无显著性,但记忆能力已接近成年鼠,只是不稳定。幼龄鼠的穿越次数少于成年鼠,在目标象限的停留时间也短于成年鼠,虽然差异不显著,但可说明其空间探索能力低,也进一步说明其记忆能力接近成年鼠。RT-PCR结果显示定位航行训练组海马Arc mRNA的表达量明显高于对照组,且成年鼠高于幼龄鼠。结论幼龄鼠瞬时记忆能力接近成年鼠,但形成稳定记忆的能力弱于成年鼠。Arc基因在幼龄鼠和成年鼠静息状态时无明显差别,但行为训练后在成年鼠海马的表达量高于幼龄鼠。

Correlation of Arc gene expression level with memory ability of young and adult rats

Objective To investigate the correlation of Arc gene expression level with the memory formation of different month-old rats.Methods Morris maze was applied to detect place navigation test and space exploration abilities of 2month old young rats and 6-month old adult rats,to test the memory formation.Arc mRNA expression level in hippocampus was tested by RT-PCR.Results The average escape latency of young rats and adult rats gradually decreased,in third day significantly lower than the first day（P0.05）,especially in young rats,showing that learning and memory abilities of young rats was fine,but their average escaping latency was still higher than adult rats,and their memory ability was closed to adult rats,but unstable.The times of young rats crossing the platform were fewer than adult rats,the duration in the target quadrant were shorter than adult rats,although the difference was not significant,showing that their space exploration abilities were lower than adult rats,further illustrating the memory ability was closed to adult rats.The results of RT-PCR showed Arc mRNA expression level in hippocampus of place navigation test groups was significantly higher than that of the control group.Conclusions The immediate memory of young rats is close to adult rats,but the formation of stable memory abilities is weaker than adult rats.Arc gene was no significant difference in the young rats and adult rats atb silent state,but after behavioral training,the expression level in the adult rats’hippocampus was higher than young rats.