MODELING INDUCED CURRENTS IN BIOLOGICAL CELLS EXPOSED TO LOW-FREQUENCY MAGNETIC-FIELDS

Interactions of low-frequency magnetic fields with biological systems have been a subject of intense scientific inquiry and public concern. Most research has been done at powerline frequencies of 50 Hz or 60 Hz . One of the key questions related to interactions of low-frequency ma gnetic fields with biological systems is which parameters of the expos ure field are responsible for observed effects. Knowledge of the induc ed electric field and current in various experimental in vitro systems is important for this purpose. The 3D impedance method is used in thi s research to model spatial patterns of induced electric fields and cu rrent in two preparations of cells. A cell monolayer with a random dis tribution of cells and a confluent monolayer of cells with gap junctio ns are considered; because of the limitations of the computational met hod, biological cells are represented by cubes rather than more realis tic shapes (e.g. spheres). The random model indicates that for higher cell densities the pattern of the induced current flow has a limited d ependence on the size and shape of the container in which the cells ar e placed, it depends mostly on the actual cell placement. Gap junction s, not surprisingly, are shown to increase the current density, but on ly if their resistance is sufficiently low. The highest current densit y occurs in the gaps.