A Possible Inductive Mechanism for Magnetogenetics

Reports of genetically conferred sensitivity to magnetic stimuli have preceded plausible mechanistic explanations. Frequently, these experiments rely on a fusion of ferritin with a transient receptor potential vanniloid channel protein, speculating associated mechanical or thermal cues. However, it has been argued compellingly that the small magnetic moment of ferritin precludes these possibilities. Here, we offer an alternative hypothesis based on stochastic resonance that does not require appreciable interaction of ferritin with the applied field. Rather, we suggest that ferritin might act merely as a localized source of high frequency inductive noise on the membrane. When combined with externally applied time-varying fields, this noise might help surmount the activation threshold of endogenous voltage-gated ion channels. To explore this concept, we use the stochastic Landau-Lifshitz-Gilbert equation to model magnetization dynamics and compare the magnetic field noise resulting from ferritin and from a 15 nm magnetite particle.