新生鼠PFOS低剂量慢暴露对成年后神经行为的影响

为观察新生鼠全氟辛烷磺酸(PFOS)低剂量慢暴露对其成年后神经行为和海马组织影响,选取出生后5-7 d雄性SD幼鼠80只,按体重随机分为4组,分别为对照组(Con)、低剂量组(P5)、中剂量组(P10)、高剂量组(P20),每组各20只。从PND7开始染毒,共染毒12周,动态记录体重,并进行水迷宫、旷场实验、滚轮实验观察神经行为变化,同时取材进行HE染色,观察海马形态学改变。结果显示与Con组比较,P20组染毒8 d后出现体重增长减缓(P0.05),4周时P10和P20组死亡率明显升高;并且P10、P20组在4周,P5组在8周时,水迷宫实验逃逸潜伏期延长,目标象限停留时间缩短;P10、P20组大鼠在4周,P5组在8周时,旷场实验中央格停留时间延长,站立次数减少,行走总距离缩短;滚轮试验中,对照组和P5组肢体运动协调能力无显著性差异。P5组在染毒12周时出现海马神经元排列紊乱,胞核固缩及胞体胀大,CA1区细胞和齿状回闩区神经前体细胞数量明显少于Con组(P0.01)。上述结果表明,大鼠幼年PFOS低剂量慢暴露可损害其成年后空间学习记忆及自主探究能力,这种损害可能与海马神经元发生不足有关

The Effect of Neonatal Exposure to Low Dose PFOS on Neural Behavior in Puberty

To observe the effect of neonatal exposure of PFOS on the neural behavior and hippocampus in adult -hood., 80 male neonatal SD rats were randomly divided into control group(Con), PFOS groups in low dose (P5), middle dose(P10) and high dose(P20), with 20 rats in each group. The PND7 rats were treatedwith PFOS by peritoneal injection till PND90, The Con groupwas treated with 0.2% Tween-80 saline.The neural behaviors were detected by water maze, open-fieldtest and rotarod test. The morphological changes in hippocampus were observed with HE staining. The results demonstrated that the mortality of rats in P10 and P20 group were higher than that in Con groupafter 4 weeks exposure(P<0.05), and the weight of rats in P20 group were lower than that in Con group after 8 d exposure(P<0.05). The escape latency was longer and the target quadrant residence time was shorter than that of the Con group in P5 group at 8weeks and in P10 and P20 group at 4weeks. The time spent at the center of enclosure was longer, the vertical rearing was less, and the ambulatory distance was shorter for P10, P20 rats at 4weeks, and for P5 rats at 8weeks than those in Con group. No significant difference was observed in the performance of rats in Con and P5 groups in rotarod test. The morphology of hippocampus of P5 rats at 12 weeks were observed and showed that the neurons were blurring with nuclear pyknosis. The number of nerve cells in CA1 and the neural precursor cells in dentate gyrus were less in P5 rats(P<0.01). These results demonstrated that chronic and low-dose exposure to PFOS in neonatal rats can impair spatial learning and memory ability in adulthood,which is associated with loss of hippocampal neurons.