Effects of exposure to different frequencies of electromagnetic fields on long-term potentiation in rat hippocampal CA1 region through intracellular Ca2+ concentration

Long-term potentiation (LTP) in the Schaffer-CA1 region of the hippocampus is closely related to learning and memory. Magnetic stimulation, as an effective physical means of regulating synaptic plasticity, has received widespread attention. However, research on the mechanism of the effect of different frequencies of magnetic fields (MFs) on LTP is relatively scarce. This article focuses on Ca2+, Na+, K+, NMDA receptors, and AMPA receptors that play important roles in the process of MF regulation of LTP. A combined electrophysiological and pharmacological approach was used to identify Ca2+ as a key factor in the modulation of LTP by MFs of different frequencies. Subsequently, further experiments revealed that low levels of intracellular Ca2+ concentration ([Ca2+](i)) intensified the inhibition of low-frequency MFs on LTP, while high levels of [Ca2+](i) enhanced the promotion effect of high-frequency MFs on LTP, indicating a positive correlation between [Ca2+](i) levels and MF regulation of LTP levels. The research results of this article may help explore the deeper relationship between different frequencies of MFs and synaptic plasticity, and they also have a certain reference value for magnetic stimulation therapy in the treatment of neurological diseases related to LTP injury or learning and memory deficits.