胚胎期暴露于甲基汞大鼠的迷宫测试

Electric maze testin rats after prenatal methylmercury exposure

为研究胚胎期甲基汞暴露对大鼠迷宫学习与记忆能力的影响 ,用不同剂量甲基汞 [0、0 .0 1、0 .0 5和 2 .0 0 mg/ (kg· d) ]于大鼠孕 6～ 9天连续灌胃染毒 ,仔鼠出生 7周时进行 Y型迷宫测试。学习记忆成绩以平均错误次数、到达安全区平均时间和主动回避率表示。整个实验采用双盲法。结果与对照组相比 ,各暴露组大鼠的平均错误次数和到达安全区平均时间显著增高 ,主动回避率显著降低 (P<0 .0 5或 P<0 .0 1) ;各组大鼠学习记忆能力无性别差异。提示甲基汞可通过胎盘屏障和乳汁进入仔鼠体内 ,影响仔鼠神经系统的发育 。

To study the changes of rat's learning and m em ory ability in maze test after prenatal methylmercury exposure,methylmercury in doses of 0 ,0 .0 1,0 .0 5 and 2 .0 0 m g/(kg· d) were fed to pregnant rats at the 6 th～ 9th day after conception.We adopted a Y- shaped electric m aze to detectlearning and memory ability of the rat offspring.Double blind was used in the experiment.The results showed that the error times and arrival time of all exposure groups were more,and active avoidance ratio of all exposure groups was less than that of control group.The differences were significant(P<0 .0 5 or P<0 .0 1) .There was no difference between male and fem ale rats.It is concluded thatm ethylmercury could affect the growth and development of central nerve system.The learning and memory ability of rat offspring was greatly dam aged.