Effects Of The Power Frequency Magnetic Fields With Different Intensities Exposure On Voltage-gated Channel Of Neurons

With the development of science and technology, a variety of household appliances and communication equipments have become increasingly popular in people's life, leading to more widely distribution of the magnetic field in the environment. Despite growing concern about the biological effects of the magnetic fields, the mechanism remains obscure. So it is necessary to get more experiment dadt and to do more theoretical analysis. The cortical neurons isolated from the mice were exposed to a 50 Hz magnetic field (1 mT,5 mT,10 mT) for 15min. Using the whole-cell patch clamp technique, the currents of voltage-gated sodium and potassuim channel were recorded, and then the effects of magnetic fields on the channels were investigated from the perspective of cellular electrophysiology. The impacts of magnetic field on the channel were evaluated by the voltage-dependence and intensity-dependence of channels, and the activation and inactivation characteristic of channels.The results of this paper are as follows. Firstly, the power frequency magnetic fields ( PFMFs 1 mT,5 mT,10 mT) affected the voltage-gated sodium channel currents of cortical neurons, 1 mT and 10 mT PFMFs exposure increased sodium channel currents, but 5 mT PFMFs inhibited sodium channel currents. In addition, different strength of PFMFs changed the activation and inactivation properties of sodium channel, but with different levels of activation and inactivation parameters. Secondly, there were significant inhibition on the transient outward potassium currents after exposure to PFMFs, but the rates of inhibition were different at different intensity of PFMFs. Moreover, compared to the control group, the characteristics of activation and inactivation were both influenced by PFMFs. Finally, PFMFs of different strength exposure inhibited the delayed rectifier potassium currents, and with the increase of the voltage depolarization, the inhibition rate curves were different. Additionly, 1 mT and 5 mT PFMFs both affected the activation characteristics of delayed rectifier potassium channel, while 10 mT PFMFs did not changed anything.The biological effects of different strength of PFMFs have been researched from the point of view of electrophysiological, using the whole-cell patch clamp technique. The results not only provide data for the research of biological effects of magnetic field, but also lay data base to reveal the mechanism of magnetic field.