中文摘要：

本文旨在探讨每天灌胃omega-3鱼油对慢性铅暴露（0.2%醋酸铅）导致的大鼠海马齿状回（dentate gyrus,DG）区突触可塑性损伤有无保护作用。将新生Wistar大鼠分为4组：正常对照组、铅组、正常＋鱼油组、铅＋鱼油组,染铅方式为饮用0.2%醋酸铅水,鱼油按0.4mL/100g体重采用灌胃方式给药,至大鼠80~90d时,4组大鼠进行海马DG区的场电位记录,记录兴奋性突触后电位（excitatory postsynaptic potential,EPSP）、群峰电位（population spike,PS）的长时程增强（long-term potentiation,LTP）。结果显示：出生后的铅暴露损伤了大鼠海马DG区的LTP;鱼油对正常对照组的LTP无显著影响,而对染铅大鼠LTP的损伤有明显的修复作用。以上结果提示omega-3鱼油可能对慢性铅暴露导致的LTP损害具有一定的保护作用。

英文摘要：

In order to evaluate the effect of omega-3 fish oil supplement by gavage （0.4 mL/100 g body weight） on the chronic lead- induced （0.2% lead acetate） impairments of long-term potentiation （LTP） in rat dentate gyrus （DG） in vivo, we designed the experi- ments which were carried out in four groups of newborn Wistar rats （the control, the lead-exposed, the control with fish oil treatment and the lead-exposed with fish oil treatment, respectively）. The excitatory postsynaptic potential （EPSP） and population spike （PS） amplitude were measured in the DG of rats with above different treatments at the age of 80-90 d in response to stimulation applied to the lateral perforant path. The results showed （1） postnatal chronic lead-exposure impaired LTP measured on both EPSP slope and PS amplitude in DG area of the hippocampus; （2） in the control rats, omega-3 fish oil had no effect on LTP while in the lead-exposed rats, omega-3 fish oil had a protective effect on LTP. These results suggest that omega-3 fish oil supplement could protect rats from the lead- induced impairment of LTP. Omega-3 fish oil might be a preventive substance in reducing LTP deficits induced by lead.