Enhancing c-fos mRNA Expression in Primary Cortical Cell Cultures with a Dynamic Magnetic Fields Device

Magnetic fields have the potential to impact biological systems and trigger various biological responses. However, the mechanisms underlying dynamic magnetic fields (DMFs), which are created by rotating magnets based on Arago's disk principle and include eddy currents, Lorentz forces, and magnetic fields, are not well understood. This study aims to investigate the effects of DMFs on gene expression in primary cultured cortical cells. To simulate DMFs, rotating magnets were used to confirm magnetic flux density, current density, and Lorentz force. Primary cortical cell cultures were then exposed to moderate-intensity DMFs with a frequency of 40 Hz for 1 h per day over 3 days. The expression of neuroplasticity-related immediate early genes, including proto-oncogene c-fos, activity-regulated cytoskeleton-associated protein (Arc) and brain-derived neurotrophic factor (BDNF) were quantified. The simulation of DMFs generated a periodic magnetic flux density of up to 131 mT, a periodic current density of up to 1.69 A/m², and a periodic Lorentz force of up to 0.88 nN in the dish. Exposure to DMFs increased c-fos mRNA expression in primary cortical cell cultures, but did not affect Arc and BDNF expression. The findings suggest that exposure of DMFs in the gamma frequency range, which may be regulated by voltage-, mechanical-, and magnetic flux-sensitive ion channels, could enhance c-fos expression in primary cortical cell cultures. The device using rotating magnets has the potential to facilitate the development of a cost-effective and user-friendly cell culture system based on the principle of Arago's disk.