A role for the magnetic field in the radiation-induced efflux of calcium ions from brain tissue in vitro.

Journal Article (Journal Article)

Two independent laboratories have demonstrated that electromagnetic radiation at specific frequencies can cause a change in the efflux of calcium ions from brain tissue in vitro. In a local geomagnetic field (LGF) at a density of 38 microTesla (microT), 15- and 45-Hz electromagnetic signals (40 Vp-p/m in air) have been shown to induce a change in the efflux of calcium ions from the exposed tissues, whereas 1- and 30-Hz signals do not. We now show that the effective 15-Hz signal can be rendered ineffective when the LGF is reduced to 19 microT with Helmholtz coils. In addition, the ineffective 30-Hz signal becomes effective when the LGF is changed to +/- 25.3 microT or to +/- 76 microT. These results demonstrate that the net intensity of the LGF is an important variable. The results appear to describe a resonance-like relationship in which the frequency of the electromagnetic field that can induce a change in efflux is proportional to a product of LGF density and an index, 2n + 1, where n = 0,1. These phenomenological findings may provide a basis for evaluating the apparent lack of reproducibility of biological effects caused by low-intensity extremely-low-frequency (ELF) electromagnetic signals. In future investigations of this phenomenon, the LGF vector should be explicitly described. If the underlying mechanism involves a general property of tissue, then research conducted in the ambient electromagnetic environment (50/60 Hz) may be subjected to unnoticed and uncontrolled influences, depending on the density of the LGF.

Full Text

Duke Authors

Cited Authors

  • Blackman, CF; Benane, SG; Rabinowitz, JR; House, DE; Joines, WT

Published Date

  • 1985

Published In

Volume / Issue

  • 6 / 4

Start / End Page

  • 327 - 337

PubMed ID

  • 3836676

International Standard Serial Number (ISSN)

  • 0197-8462

Digital Object Identifier (DOI)

  • 10.1002/bem.2250060402


  • eng

Conference Location

  • United States