Frequency-window effects of subthreshold electric fields on neuronal discharges of active neurons

With a two-compartment model, we investigate how subthreshold sinusoidal electric fields (EFs) affect neuronal discharges of active neurons by adjusting the field intensity and the field frequency. It´s found that apparent fluctuations on neuronal discharges only appear within several stimulus frequency windows. And when the field frequency is adjusted to be close to the multiple of the intrinsic spiking rate, the fluctuations are maximized. Compared with the change in neuronal spiking rate, the modulation of neuronal spike timing induced by subthreshold EFs is stronger. Additionally, field effects on neuronal discharges are enhanced by the increasing stimulus intensity. Our results provide useful guidance to understand how subthreshold sinusoidal EFs modulate neuronal discharges, which may help to improve the future electromagnetic therapy.