Static-Magnetic-Fields of Dental Magnets Influence Voltage-gated Sodium Channels of Neurons

OBJECTIVES: To study the effects of static-magnetic-fields (SMF) produced by permanent dental magnets on the electrophysiological properties of voltage-gated sodium channels (VGSCs) on neurons. METHODS: Acutely dissociated TRGNs of neonatal SD rats and sciatic nerve cords of bull frog were exposed to 125mT and 12.5mT SMF in exposure devices which were made to simulating the fields of commonly used dental magnets. Whole-cell patch-clamp recordings were carried out to observe the changes of VGSCs currents on TRGNs as they were loaded by SMF. Neural electrophysiology recordings were performed on sciatic nerve cords to study such effects on tissue level. RESULTS: (1) Activation and inactivation kinetics of VGSCs currents were found being altered while TRGNs were exposed to 125mT SMF, but no change was observed under 12.5mT SMF exposure. (2) 125mT and 12.5mT SMF had no effect on the excitability as well as the conduction behaviors of bull-frog sciatic nerves in vitro. CONCLUSIONS: Those experimental findings suggested that the moderate-intensity SMF of dental magnets had certain effects on the electrophysiological characteristics of ion channel on cellular level. Such influences might be intensity-dependent and were not shown on the tissue level. The mechanism underlying those changes was believed to be related to the magnetic reorientation of membrane phospholipids caused by moderate-intensity SMF through diamagnetic anisotropy effects.