A Larmor precession-dynamical systems model for μT range magnetic field bioeffects

A dynamical systems approach is proposed to treat the competitive kinetics of ion binding and dissociation at a signaling molecule, taking into consideration the key roles played by ion hydration and thermal noise. A bistable potential well represents bound and unbound states, with thermal noise providing the driving force for the ion binding process. It is postulated that the effect of the magnetic field is to induce precessional motion at the Larmor frequency in polarized water molecules forming hydration layers at the binding site. The resulting modulation of hydration orientation angles alters the local dielectric constant at the binding site, resulting in changes in kinetics of ion binding. A threshold in the 0.1-1 μT range for magnetic field effects on ionic orientation in the presence of thermal noise is predicted, based on the lifetime of hydration at a molecular cleft. Low frequency AC magnetic fields, for which the effects of the induced electric field may be neglected, produce results similar to those for static fields and also exhibit resonance effects for frequencies at or near the characteristic interwell hopping rate for the ion. A second type of resonance condition at the Lamor frequency is predicted for static and AC magnetic fields in perpendicular orientation only