Li Shuangyan, Wen Xuehan, Sang Haojun, Xu Guizhi
State Key Laboratory of Reliability and Intelligence of Electrical Equipment, School of Electrical Engineering, Hebei University of Technology, Tianjin 300130, P.R.China;Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, School of Electrical Engineering, Hebei University of Technology, Tianjin 300130, P.R.China.
State Key Laboratory of Reliability and Intelligence of Electrical Equipment, School of Electrical Engineering, Hebei University of Technology, Tianjin 300130, P.R.China;Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, School of Electrical Engineering, Hebei University of Technology, Tianjin 300130,
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi. 2018 Dec 25;35(6):829-836. doi: 10.7507/1001-5515.201806004.
The possible influence of electromagnetic field (EMF) on the function of neural systems has been widely concerned. In this article, we intend to investigate the effects of long term power frequency EMF exposure on brain cognitive functions and it's mechanism. The Sprague-Dawley (SD) rats were randomly divided into 3 groups: the rats in EMF Ⅰ group were placed in the 2 mT power frequency EMF for 24 days. The rats in EMF Ⅱ group were placed in the 2 mT power frequency EMF for 48 days. The rats in control group were not exposed to the EMF. Then, the 16 channel local field potentials (LFPs) were recorded from rats' prefrontal cortex (PFC) in each group during the working memory (WM) tasks. The causal networks of LFPs were also established by applying the directed transfer function (DTF). Based on that, the differences of behavior and the LFPs network connection patterns between different groups were compared in order to investigate the influence of long term power frequency EMF exposure on working memory. The results showed the rats in the EMF Ⅱ group needed more training to reach the task correction criterion (over 80%). Moreover, the causal network connection strength and the global efficiency of the rats in EMF Ⅰ and EMF Ⅱ groups were significantly lower than the corresponding values of the control group. Meanwhile, significant differences of causal density values were found between EMF Ⅱ group and the other two groups. These results indicate that long term exposure to 2 mT power frequency EMF will reduce the connection strength and the information transfer efficiency of the LFPs causal network in the PFC, as well as the behavior performance of the rats. These results may explain the effect of EMF exposure on working memory from the view of neural network connectivity and provide a support for further studies on the mechanism of the effect of EMF on cognition.
电磁场（EMF）对神经系统功能的可能影响已受到广泛关注。在本文中，我们旨在研究长期工频电磁场暴露对大脑认知功能及其机制的影响。将Sprague-Dawley（SD）大鼠随机分为3组：EMFⅠ组大鼠置于2 mT工频电磁场中24天。EMFⅡ组大鼠置于2 mT工频电磁场中48天。对照组大鼠不暴露于电磁场。然后，在工作记忆（WM）任务期间记录每组大鼠前额叶皮质（PFC）的16通道局部场电位（LFP）。还通过应用定向传递函数（DTF）建立LFP的因果网络。在此基础上，比较不同组之间行为和LFP网络连接模式的差异，以研究长期工频电磁场暴露对工作记忆的影响。结果显示，EMFⅡ组大鼠需要更多训练才能达到任务校正标准（超过80%）。此外，EMFⅠ组和EMFⅡ组大鼠的因果网络连接强度和全局效率显著低于对照组的相应值。同时，EMFⅡ组与其他两组之间的因果密度值存在显著差异。这些结果表明，长期暴露于2 mT工频电磁场会降低PFC中LFP因果网络的连接强度和信息传递效率，以及大鼠的行为表现。这些结果可能从神经网络连通性的角度解释电磁场暴露对工作记忆的影响，并为进一步研究电磁场对认知影响的机制提供支持。
