Study on Effects of electromagnetic Field to Biological Clock

我们研究了电磁场对生物钟的影响。重点研究了脉冲磁场对大脑皮层功能的影响。利用神经纤维兴奋特性模型分析了大脑皮层对脉冲磁场的响应。研究了大脑皮层的输入和输出神经元--锥体神经元的特性。根据锥体细胞垂直于皮质表面排列的事实，似乎可以合理地假设，皮层上感应电场的大部分垂直于皮质表面的部位是脉冲磁场容易产生神经兴奋的部位。我们通过脉冲磁场刺激初级运动皮质的实验验证了这一观点。测量脉冲磁场刺激大脑皮层诱发的肌电。结果表明，垂直于皮层表面的感应电场分量是影响大脑皮层功能的主要因素。我们将在本研究结果的基础上，进一步研究电磁场对生物钟系统的影响。

We have investigated effects of electromagnetic fields to biological clock. The effects of pulsed magnetic field to the function of cerebral cortex were focused. The response of cerebral cortex to the pulsed magnetic fields was analyzed by using the model of properties of excitation of nerve fiber. The properties of pyramidal neurons which are the input and output neurons in the cortex were examined. On the basis of the fact that pyramidal cells are aligned perpendicular to the cortical surface, it seems reasonable to suppose that the site on a cortex with a great component of the induced electric field perpendicular to the cortical surface is the stimulating site where nerve excitation readily occurs by pulsed magnetic fields. We verified this notion by the experiments on the stimulation of primary motor cortex with pulsed magnetic fields. The electromyography evoked by the stimulation of the cortex with pulsed magnetic fields was measured. The results show that the component of the induced electric field perpendicular to the cortical surface is principal factor of effects to the function of cerebral cortex. We are going to carry out further studies of the effects of electromagnetic fields on the biological clock system based on the results obtained in this study.