出生后接触氰戊菊酯对仔鼠神经行为发育及学习记忆的影响

Neurobehavior and learning and memory of mice after postnatal exposure to fenvalerate

目的观察出生后早期有限次数氰戊菊酯(FEN)染毒对ICR仔鼠神经发育毒性影响,尤其是对成年后学习记忆的影响。方法仔鼠自出生第3天开始腹腔注射染毒,隔天一次,连续6次,分5、0.5和0.05mg/kg3个FEN染毒组及二甲基亚枫(DMSO)和生理盐水2个对照组,DMSO11只,其余各组均为16只。观察仔鼠的一般生理和神经行为发育情况,进行旷场实验、平衡木实验、学习记忆功能测试——包括新物体识别、水迷宫。结果染毒期间,仔鼠躯体感觉运动发育受影响,但至青年期在平衡木测试中,各组已无差异;在旷场实验中,反映自发性活动和焦虑情绪的指标在各组间均无差异;成年后在Morris水迷宫空间探索实验中,高剂量组小鼠在60s内穿越平台次数减少(P<0.05)。结论出生后早期有限次数接触低剂量FEN在染毒期间会影响仔鼠躯体感觉运动功能发育,发育至青年期,小鼠的感觉运动功能得以恢复;但出生后早期接触低剂量氰戊菊酯,会影响小鼠成年后的空间记忆能力。

Objective To evaluate the developmental neurotoxicity of low-dose Fenvalerate exposure during postnatal period in mice with emphasis on learning and memory. Methods 1CR mice pups were administered by intraperitoneal injections （i. p. ） of Fenvalrate （DMSO solution） at doses of 0, 0.05, 0.5 and 5.0 mg/kg body weight （bw） every other day from postnatal days （PND） 3-13. Control animals received saline or DMSO by the same route. Each group Consisted of 16 animals except DMSO Consisted of 11, Various markers of growth and developemnt were evaluated. Neurobehavioral assessments included： open-field, horizontal bar task, novel-object recognition task and Morris water maze（MWM）. Results There was a trend towards decreased vaginal opening time and discrimination ratio in novel-object recognition task in the high dose group. FEN-exposure induced reversible effects on sensorimotor activity which were measured by negative geotaxis test （ PND7 ）, and horizontal bar task （ PND 70 ）. FEN-exposure did not alter mice behavior in open-field, but FEN-exposure （dose group 5.0 mg/kg body weight） decreased number of platform-site crossovers in probe trial of MWM test compared to DMSO control. Conclusions The results suggest that early postnatal exposure to FEN affects spatial memory in adult mice.