中文摘要：

目的研究纳米硒对1800MHz射频场（radiofrequency fields，RF）暴露小鼠认知能力的影响，并探讨其作用机制。方法将雄性昆明小鼠随机分为对照组，纳米硒低、中和高剂量组（Se浓度为2、4和8μg／ml），每只0．5ml／d，对照组给予同体积蒸馏水，连续50d。每组又各自分为RF假暴露组（Sham）及不同RF暴露时间组（30和120rain）。在添加纳米硒的第21天，RF两组每天分别暴露于1800MHzRF（208μW／cm^2，SAR：0．2858W／kg）30和120min，连续30d，Sham组处于同样RF暴露装置但不给予射频信号。利用Y一型迷宫试验测定认知能力，同时测定小鼠大脑组织中的丙二醛（MDA）、γ-氨基丁酸（GABA）、谷氨酸（Glu）、乙酰胆碱（Ach）水平及过氧化氢酶（CAT）和谷胱甘肽过氧化物酶（GSH—Px）活性。结果RF损伤了小鼠的学习和记忆能力，降低了CAT和GSH—Px活性及Ach水平，增加了GABA、Glu和MDA水平。纳米硒明显提高了RF暴露小鼠的认知能力，降低了GABA、Glu和MDA水平，增加了CAT和GSH—Px活性及Ach水平。结论纳米硒能改善RF所引起的小鼠认知功能损伤，其作用机制可能与通过增加抗氧化能力降低自由基损伤并改变神经递质水平有关。

英文摘要：

Objective To study the effects of nano-selenium （NSe） on cognition performance of mice exposed to 1800 MHz radiofrequency fields （RF）. Methods Male mice were randomly divided into four groups, control and nano-Se low, middle and high dose groups （L, M, H）. Each group was sub-divided into three groups, RF 0 min, RF 30 rain and RF 120 rain. Nano-se solution （2, 4 and 8 p.g/ml） were administered to mice of L, M, H groups by intra-gastrie injection respectively, 0.5 ml/d for 50 days, the conctral group were administered with distilled water. At the 21st day, the mice in RF subgroup were exposed to 208 p.W/em2 1800 MHz radiofrequency fields （0, 30 and 120 min/d respectively） for 30 days. The cognitive ability of the mice were tested with Y-maze. Further, the levels of MDA, GABA, Glu, Ach and the activities of CAT and GSH- Px in cerebra were measured. Results Significant impairments in learning and memory （P 〈0.05） were observed in the RF 120 rain group, and with reduction of the Ach level and the activities of CAT and GSH-Px and increase of the content of GABA, Glu and MDA in cerebrum. NSe enhanced cognitive performance of RF mice, decreased GABA, Glu and MDA levels, increased Ach levels, GSH-Px and CAT activities. Conclusion NSe could improve cognitive impairments of mice exposed to RF, the mechanism of which might involve the increasing antioxidation, decreasing free radical content and the changes of cerebra neurotransmitters.