Modeling the Influence of a Steady Magnetic Field on Action Potential Generation in Neurons

In spite of increasing public concern about the impact of magnetic fields on health, use of magnetic devices in the practice of clinical medicine is on the rise. However, the influence of a constant magnetic field on action potential generation and conduction in neurons is yet to be definitively explained. In this work a physical model is presented which accounts for the influence of a steady magnetic field on neuron excitability. The validity of the proposed model is verified based on simulations using a public-domain software known as HHSim, which implements the Hodgkin-Huxley model equations in MATLABTM. The proposed model accounting for the influence of a steady magnetic field on neuron excitability is in agreement with experimental observations as well as simulations based on the Hodgkin-Huxley model. Simulations using the HHSim software verified the reduction in the amplitude of the depolarizing excitation current in proportion to the magnitude of the magnetic flux density leading to action potential suppression. The separation of ionic charge resulting from the magnetic force acting on the mobile ions in the intracellular space was introduced as the origin of a Hall electric field in a direction perpendicular to action potential transmission along the axon. The current flow associated with this electric field, in turn, leads to the reduction of the ionic current available for discharging the membrane capacitance, thereby reducing the neuron excitability