Modeling of membrane potential dynamics induced by electromagnetic stimulation

Transcranial Magnetic Stimulation (TMS), transcranial Direct Current Stimulation (tDCS), and other electromagnetic stimulation modalities have been used to apply neuromodulation but their working mechanism remains largely unknown. This study aims to introduce a computer model for membrane potential dynamics induced by electromagnetic stimulation. In the simulation, realistic neuron morphologies are segmented into multiple compartments to calculate membrane potential changes numerically. This model is validated on multiple types of neocortical neurons. Membrane potential convergence and intracellular potential uniformity at steady state have been confirmed on neurons with insulating membrane. Minimum action potential firing thresholds measured under uniform field stimulation show that different types of neurons have distinct thresholds thus may have divergent responses when treated by neuromodulation. Simulated thresholds are compared with data obtained from in vitro experiment and no significant difference is observed. These results indicate that the simulation can successfully mimic neuron membrane dynamics induced by electromagnetic stimulation.