Extreme low frequency electromagnetic field stimulation induces metaplastic-like effects on LTP/ LTD

Y Zheng, C X Tian, L Dong, X X Ma, Y Gao, C Xiong, K H Zhang, C S Li
2019 IEEE Access  
In modern societies, people are more likely to be exposed to technological devices that emit extreme low frequency (ELF, < 300 Hz)-electromagnetic fields (EMFs). Although ELF-EMFs are successfully used as therapeutic agents in psychiatry treatment and rehabilitation practices, they are also considered to be environmental pollutants that pose a risk to human health. However, several studies have suggested that ELF-EMFs stimulation has the potential to ameliorate learning and memory processes in
more » ... umans. Given that the underlying mechanisms of magnetic stimulation on the brain are not fully understood, this study aimed to investigate the effects of ELF-EMFs in learning and memory formation. Sprague-Dawley rats were used as a model system to evaluate learning and memory mechanisms based on the synaptic plasticity of the Schaffer-CA1 pathway in hippocampal slices using ELF-EMFs stimulation. Parameters were selected based on previous experiments (i.e., 15 hertz [Hz], 2 militesla [mT]), during, and after plasticity induction, basic frequencies of 1, 5, 20 and 100 Hz were applied and an on-line ELF-EMFs stimulation drive was used together, which previously defined as preceding, middle and post stimulation. Our results showed that the greatest effect on synaptic plasticity was observed when ELF-EMFs were paired with a plasticity induction protocol. Importantly, ELF-EMFs did not affect synapses that were weakly active or in synapses containing N-methyl-D-aspartate (NMDA) receptors that were blocked. This study highlights the metaplastic-like role of ELF-EMFs, acting as modulators of synaptic activity processes,as well as their regulation by NMDA receptor-dependent synaptic plasticity. INDEX TERMS Preceding, middle and post ELF-EMFs stimulation, hippocampal slices, LTP and LTD, metaplasticity, NMDA receptors.
doi:10.1109/access.2019.2947690 fatcat:2gtzzhota5hhndtohmxvdtnwda