Modeling of inhomogeneous electromagnetic fields in the nervous system: a novel paradigm in understanding cell interactions, disease etiology and therapy

All major processes in the nervous system depend on interactions between cells and nerve fibers. In this work we present a novel model of inhomogeneous electromagnetic fields originating from nerve fibers and delineate their influence on cells. By expanding Hodgkin-Huxley's applied current into axial current, governed byJ(i)(J+1) = K x J(i)(j), we reveal that cell-with-neuron interactions are regulated by the strength of the electromagnetic fields, which are homogeneous up to 2.066 mu m or 6.606 mu m away from neurilemma and axolemma, respectively. At the nodes of Ranvier, these fields reach strengths of 3.0 x 10(-12)T, while at the myelinated segments they only peak at 2.3 x 10(-12)T. These are the same fields which are, due to inhomogeneity, detected as 1,000 times weaker by magnetoencephalography. Considering the widespread occurrence of neurodegenerative disorders, our model reveals that a 50% demyelination increases the field strength by 0.35 x 10(-12)T, while a complete demyelination increases it by 0.7 x 10(-12)T. Since this suggests that the inhomogeneous electromagnetic fields around neurons play a role in physiological and pathological processes, including cell-to-neuron and cell-to-cell communication, their improved understanding opens up new therapeutic strategies based on electromagnetic field modulation or cell's surface charge alteration.