Hao Yanhui, Liu Weiqi, Xu Zhengtao, Jin Xing, Ye Yumeng, Yu Chao, Hu Cuicui, Zuo Hongyan, Li Yang
Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China.
Life Science Department, Foshan University, Foshan, China.
Front Cell Neurosci. 2022 Jun 29;16:898164. doi: 10.3389/fncel.2022.898164. eCollection 2022.
Electromagnetic pulse (EMP) is a high-energy pulse with an extremely rapid rise time and a broad bandwidth. The brain is a target organ sensitive to electromagnetic radiation (EMR), the biological effects and related mechanisms of EMPs on the brain remain unclear. The objectives of the study were to assess the effects of EMP exposure on mouse cognitions, and the neuronal calcium activities under different cases of real-time exposure and post exposure. EMP-treated animal model was established by exposing male adult C57BL/6N mice to 300 kV/m EMPs. First, the effects of EMPs on the cognitions, including the spatial learning and memory, avoidance learning and memory, novelty-seeking behavior, and anxiety, were assessed by multiple behavioral experiments. Then, the changes in the neuronal activities of the hippocampal CA1 area were detected by fiber photometry in both cases of during real-time EMP radiation and post-exposure. Finally, the structures of neurons in hippocampi were observed by optical microscope and transmission electron microscope. We found that EMPs under this condition caused a decline in the spatial learning and memory ability in mice, but no effects on the avoidance learning and memory, novelty-seeking behavior, and anxiety. The neuron activities of hippocampal CA1 were disturbed by EMP exposure, which were inhibited during EMP exposure, but activated immediately after exposure end. Additionally, the CA1 neuron activities, when mice entered the central area in an Open field (OF) test or explored the novelty in a Novel object exploration (NOE) test, were inhibited on day 1 and day 7 after radiation. Besides, damaged structures in hippocampal neurons were observed after EMP radiation. In conclusion, EMP radiation impaired the spatial learning and memory ability and disturbed the neuronal activities in hippocampal CA1 in mice.
电磁脉冲（EMP）是一种上升时间极快且带宽很宽的高能脉冲。大脑是对电磁辐射（EMR）敏感的靶器官，EMP对大脑的生物学效应及相关机制尚不清楚。本研究的目的是评估EMP暴露对小鼠认知的影响，以及在实时暴露和暴露后不同情况下的神经元钙活性。通过将成年雄性C57BL/6N小鼠暴露于300 kV/m的EMP中建立EMP处理的动物模型。首先，通过多项行为实验评估EMP对认知的影响，包括空间学习和记忆、回避学习和记忆、新奇探索行为和焦虑。然后，在实时EMP辐射期间和暴露后两种情况下，通过光纤光度法检测海马CA1区的神经元活动变化。最后，通过光学显微镜和透射电子显微镜观察海马神经元的结构。我们发现，在此条件下的EMP导致小鼠空间学习和记忆能力下降，但对回避学习和记忆、新奇探索行为及焦虑无影响。EMP暴露会干扰海马CA1区的神经元活动，在EMP暴露期间受到抑制，但在暴露结束后立即被激活。此外，在辐射后第1天和第7天，当小鼠在旷场（OF）试验中进入中央区域或在新物体探索（NOE）试验中探索新事物时，CA1神经元活动受到抑制。此外，EMP辐射后观察到海马神经元结构受损。总之，EMP辐射损害了小鼠的空间学习和记忆能力，并干扰了海马CA1区的神经元活动。
