Comparison of ELF-EMFs stimulation with current stimulation on the regulation of LTP of SC-CA1 synapses in young rat hippocampus

Background: Long-term potentiation (LTP) is an important functional indicator for synaptic plasticity. Extremely low frequency electromagnetic fields (ELF-EMFs) are a physical means to regulate LTP, which induce induced currents. It is unknown whether induced current is the key factor when LTP is regulated by ELF-EMFs. New Method: A method is proposed for calculating the current value induced by ELF-EMFs. Then, a comparison of ELF-EMFs with current on the regulation of theta-burst or high-frequency stimulation (TBS/HFS)-LTP was performed. Results: The LTP after ELF-EMFs and μA current regulation was significantly reduced. The regulatory effect of 0.1 μA current on LTP was similar with 100 Hz/2 mT ELF-EMFs, while 0.2 μA had a stronger regulatory effect than 200 Hz/2 mT on HFS-LTP. Comparison with Existing Methods: Most of the existing methods were used to calculate the induced current in human models, while we present a more accurate model for calculating the induced current induced by ELF-EMFs in the rat brain slices. Conclusions: This work indicated that μA current and ELF-EMFs stimulation reduced LTP. Also, we demonstrated that the regulatory effect of ELF-EMFs on LTP is not entirely deriving from the induced current, since its magnetic mechanism might have played a certain role.