Theoretical evaluation of cell membrane ion channel activation by applied magnetic fields

This letter re-examines a recently published calculation of the forces exer ted on a membrane ion channel by a cation passing through in the presence o f an externally applied magnetic field. We show here, in contradiction to t he originally published calculation, that the forces generated due to the L orentz force of the magnetic field on the cation are negligible compared wi th the forces required to activate an ion channel protein conformation chan ge associated with the gating of the channel.