中文摘要：

目的观察百草枯（PQ）对发育期C57BL／6J小鼠神经发育的毒性作用，并探讨百草枯对小鼠学习记忆的影响。方法80只出生21日龄的仔鼠分为对照组（生理盐水）、1．25、2．5、5、10mg／（kg·d）五组，灌胃染毒百草枯，每天一次，连续30d。观察小鼠的一般生理和神经行为发育情况，并在染毒结束后进行Morris水迷宫实验和避暗实验，测试小鼠的学习记忆功能。神经行为学测试结束后取小鼠大脑，称重并进行病理检查，同时利用透射电镜观察各组小鼠中脑黑质部超微结构。结果染毒期间小鼠一般状况没有明显变化，染毒结束后各组体重没有统计学差异；在Morris水迷宫测试中，各组差异没有统计学意义，而避暗实验中与对照组相比，高剂量组的避暗潜伏期延长，差异有显著性（P〈0．05）；在病理切片和透射电镜观察中，在高剂量组分别观察到黑质细胞减少和神经元细胞凋亡。结论百草枯暴露对发育期小鼠成年后神经行为有影响，同时会使小鼠成年后出现脑组织的病理变化，发生器质性的病变。

英文摘要：

Objective To observe the effect of paraquat on neurobehavioral development and learning ability in C57BL/6J mice. Methods Eighty neonatal C57BL/6J mice were randomly divided into five groups, i.e. saline （ the control group） , 1.25 mg/kg/d, 2. 5 mg/kg/d, 5 mg/kg/d, and 10 mg/kg/d paraquat groups. The chemical was given by gavage in a volume of 0. 1 mL/10 g body weight for 30 days. Neural behaviors were examined by Morris water maze test and passive avoidance task test after paraquat administration. The brain weight and histological changes were examined. Ultra- structural： changes of the substantia nigra were observed under the transmission electron microscope. Results No signifi- cant changes of body weight was observed among groups and during the Morris water maze test （P 〉 0. 05）. The results of passive avoidance task test in the high dose group was significantly longer than that in the control group （P 〈 0. 05 ）. Brain lesions were observed by both light and transmission electron microscopy. Conclusion C57BL/6J mice exposed to pa- raquat during the developmental period cause behavior alterations and pathological and biochemical changes in the brain.