A proposed mechanism for the action of strong static magnetic fields on biomembranes.

Experimental studies have demonstrated a temperature dependent effect by strong static magnetic fields on synaptic function. It is proposed that these findings may be explained by the diamagnetic properties of membrane phospholipids. The change in diamagnetic anisotropy coincidental with membrane thermotropic phase transition is responsible for the temperature dependence of this phenomenon and provides insight into the mechanism of action of these fields. At the prephase transition temperature highly diamagnetic anisotropic gel phase domains exist within a more fluid liquid-crystal phase. The partial magnetic reorientation of these domains results in membrane distortion and, thereby, functional impairment of contiguous ion specific channels. This mechanism adequately explains observations of the effects of static magnetic fields both on the central nervous system and at the neuromuscular junction. It is suggested that the same mechanism may be operative in other biosystems.