Ion Parametric Resonance Research Articles

A physical analysis of the ion parametric resonance model

We show, in elementary terms, using for the most part only elementary mathematics, the physical bases for the ion parametric resonance model so as to clarify the assumptions and consequences of the model. The analysis shows why, contrary to earlier conclusions, no combination of weak DC and AC magnetic fields can modify the transition rate to the ground state of excited ions. Although reinterpretations of the biological consequences of the motion of the excited ions circumvent that particular objection to the model, those changes introduce other difficulties. Also, other objections to the mechanism still stand; hence the model cannot account for any purported biological effects of weak extremely low frequency magnetic fields. Bioelectromagnetics 19:181–191, 1998. © 1998 Wiley-Liss, Inc.

A physical analysis of the ion parametric resonance model

We show, in elementary terms, using for the most part only elementary mathematics, the physical bases for the ion parametric resonance model so as to clarify the assumptions and consequences of the model. The analysis shows why, contrary to earlier conclusions, no combination of weak DC and AC magnetic fields can modify the transition rate to the ground state of excited ions. Although reinterpretations of the biological consequences of the motion of the excited ions circumvent that particular objection to the model, those changes introduce other difficulties. Also, other objections to the mechanism still stand; hence the model cannot account for any purported biological effects of weak extremely low frequency magnetic fields.

Hypothetical Biophysical Mechanisms for the Action of Weak Low Frequency Electromagnetic Fields at the Cellular Level

Power-line frequency electric fields of 1 mV.m-1 in the body can be induced by external electric fields of 10 kV.m-1 and by magnetic fields of 50 µT through the Faraday effect. Constraints from physical principles show that such internal fields are unlikely to generate any biological effects and fields less than 0.1 mV.m-1 must be ineffective. Moderately strong power-line frequency magnetic fields may affect biology through the direct interaction of the fields with the magnetic moments of ferrimagnetic materials in the body and through effects on radical pair recombination as a consequence of the interaction of the fields with electron magnetic moments. However, magnetic fields smaller than 50 µT (500 mG) are unlikely to affect biology, and fields less than 5 µT cannot do so. Ion Cyclotron Resonance and Ion Parametric Resonance models of biological effects of the interaction of power-line frequency magnetic fields with the magnetic moments of ions are not in accord with fundamental physical principles.

The effects of weak extremely low frequency magnetic fields on calcium/calmodulin interactions

Mechanisms by which weak electromagnetic fields may affect biological systems are of current interest because of their potential health effects. Lednev has proposed an ion parametric resonance hypothesis (Lednev, 1991, Bioelectromagnetics, 12:71-75), which predicts that when the ac, frequency of a combined dc-ac magnetic field equals the cyclotron frequency of calcium, the affinity of calcium for calcium-binding proteins such as calmodulin will be markedly affected. The present study evaluated Lednev's theory using two independent systems, each sensitive to changes in the affinity of calcium for calmodulin. One of the systems used was the calcium/calmodulin-dependent activation of myosin light chain kinase, a system similar to that previously used by Lednev. The other system monitored optical changes in the binding of a fluorescent peptide to the calcium/calmodulin complex. Each system was exposed to a 20.9 microT static field superimposed on a 20.9 microT sinusoidal field over a narrow frequency range centered at 16 Hz, the cyclotron frequency of the unhydrated calcium ion. In contrast to Lednev's predictions, no significant effect of combined dc-ac magnetic fields on calcium/calmodulin interactions was indicated in either experimental system.

Effect of AC and DC Magnetic Field Orientation on Nerve Cells

Recent tests of the influence of parallel ac and dc magnetic fields on neurite outgrowth in PC-12 cells showed good agreement with the predictions of an ion parametric resonance model. However, experimental results from earlier work involving both a perpendicular (160 mG) and a parallel (366 mG) dc magnetic field were not as consistent with the ion parametric resonance model predictions. Test results reported here show that the cell response to perpendicular ac and dc magnetic fields is distinct and predictably different from that found for parallel ac and dc magnetic fields, and that the response to perpendicular fields is dominant in an intensity-dependent nonlinear manner.

Modeling biological effects from magnetic fields

Research investigating how electromagnetic fields (EMF) might influence biological systems has suffered from the absence of a working experimental model that defines relationships between all the physical exposure parameters required to produce a biological effect. As a result, when these variables are not controlled from one experiment to another, many experimental results cannot be replicated. Recently, Blanchard and Blackman [1994] developed an ion parametric resonance (IPR) model to predict how parallel DC and low frequency AC magnetic fields might influence biological systems. Further, the IPR model has something different from previous models in this area: it is supported by an extensive, and growing, body of experimental data.

The ion parametric resonance model predicts magnetic field parameters that affect nerve cells

An ion parametric resonance (IPR) model recently developed by Blanchard and Blackman predicts distinct magnetic field interactions with biological systems based on a selective relation among four factors: the flux density of the static magnetic field, the frequency and flux density (Bac) of the parallel ac magnetic field, and the charge-to-mass ratio of ions of biological relevance. To test this model, PC-12 cells stimulated by nerve growth factor to produce neurites were exposed for 23 h in a 5% CO2 incubator using a multiple-coil exposure system to produce 45 Hz ac and dc (366 mG parallel to ac; less than 2 mG perpendicular to ac) magnetic fields. Our earlier work showed a cycle of inhibition/no inhibition of neurite outgrowth consistent with the IPR model predictions for Bac exposures between 0 and 468 mG rms. The work described here tests neurite outgrowth over a broader range of Bac (233-1416 mG rms). The experimental results remain consistent with earlier results, and with IPR model predictions of a second cycle of inhibition, return to control values, followed by a third cycle of inhibition of neurite outgrowth. These responses support the fundamental relationships predicted by the IPR model. The results have broad significance for biology.

Evaluation of whole-animal data using the ion parametric resonance model.

Changes observed in the behavioral response of land snails from exposure to parallel ac and dc magnetic fields demonstrate limited agreement with the predictions of an interaction model proposed by Lednev and the predictions of a recently proposed ion parametric resonance (IPR) model. However, the inadequate number of reported data points, particularly in a critical exposure range, prevents unambiguous application of either the Lednev or the IPR model.

Frequency-dependent interference by magnetic fields of nerve growth factor-induced neurite outgrowth in PC-12 cells.

We have shown that 50 Hz sinusoidal magnetic fields within the 5-10 microTesla (microT) rms range cause an intensity-dependent reduction in nerve growth factor (NGF) stimulation of neurite outgrowth (NO) in PC-12 cells. Here we report on the frequency dependence of this response over the 15-70 Hz range at 5 Hz intervals. Primed PC-12 cells were plated in collagen-coated, 60 mm plastic petri dishes with or without 5 ng/ml NGF and were exposed to sinusoidal magnetic fields for 22 h in a CO2 incubator at 37 degrees C. One 1,000-turn coil, 20 cm in diameter, generated vertically oriented magnetic fields. The dishes were stacked on the center axis of the coil to provide a range of intensities between 3.5 and 9.0 microT rms. The flux density of the ambient DC magnetic field was 37 microT vertical and 19 microT horizontal. The assay consisted of counting over 100 cells in the central portion (radius < or = 0.3 cm) of each dish and scoring cells positive for NO. Sham exposure of cells treated identically with NGF demonstrated no difference in the percentage of cells with NO between exposed and magnetically shielded locations within the incubator. Analysis of variance demonstrated flux density-dependent reductions in NGF-stimulated NO over the 35-70 Hz frequency range, whereas frequencies between 15 Hz and 30 Hz produced no obvious reduction. The results also demonstrated a relative maximal sensitivity of cells at 40 Hz with a possible additional sensitivity region at or above 70 Hz. These findings suggest a biological influence of perpendicular AC/DC magnetic fields different from those identified by the ion parametric resonance model, which uses strictly parallel AC/DC fields.

Reply to comments on “clarification and application of an ion parametric resonance model for magnetic field interactions with biological systems”

Reply to comments on “clarification and application of an ion parametric resonance model for magnetic field interactions with biological systems”

Comments on “clarification and application of an ion parametric resonance model for magnetic field interactions with biological systems,” by Blanchard and Blackman

Comments on “clarification and application of an ion parametric resonance model for magnetic field interactions with biological systems,” by Blanchard and Blackman

Comments on “clarification and application of ion parametric resonance model for magnetic field interactions with biological systems” by Blanchard and Blackman

BioelectromagneticsVolume 16, Issue 4 p. 268-269 Comment Comments on “clarification and application of ion parametric resonance model for magnetic field interactions with biological systems” by Blanchard and Blackman V. V. Lednev, V. V. Lednev Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, RussiaSearch for more papers by this author V. V. Lednev, V. V. Lednev Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, RussiaSearch for more papers by this author First published: 1995 https://doi.org/10.1002/bem.2250160410Citations: 10AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume16, Issue41995Pages 268-269 RelatedInformation

Reply to comments on “clarification and application of ion parametric resonance model for magnetic field interactions with biological systems”

Reply to comments on “clarification and application of ion parametric resonance model for magnetic field interactions with biological systems”

Empirical test of an ion parametric resonance model for magnetic field interactions with PC-12 cells.

A companion paper describes a predictive ion parametric resonance (IPR) model of magnetic field interactions with biological systems based on a selective relation between the ratio of the flux density of the static magnetic field to the AC magnetic field and the charge-to-mass ratio of ions of biological relevance. Previous studies demonstrated that nerve growth factor (NGF)-stimulated neurite outgrowth (NO) in PC-12 cells can be inhibited by exposure to magnetic fields as a function of either magnetic field flux density or AC magnetic field frequency. The present work examines whether the PC-12 cell response to magnetic fields is consistent with the quasi-periodic, resonance-based predictions of the IPR model. We tested changes in each of the experimentally controllable variables [flux densities of the parallel components of the AC magnetic field (Bac) and the static magnetic field (Bdc) and the frequency of the AC magnetic field] over a range of exposure conditions sufficient to determine whether the IPR model is applicable. A multiple-coil exposure system independently controlled each of these critical quantities. The perpendicular static magnetic field was controlled to less than 2 mG for all tests. The first set of tests examined the NO response in cells exposed to 45 Hz Bac from 77 to 468 mG(rms) at a Bdc of 366 mG. Next, we examined an off-resonance condition using 20 mG Bdc with a 45 Hz AC field across a range of Bac between 7.9 and 21 mG(rms). Finally, we changed the AC frequency to 25 Hz, with a corresponding change in Bdc to 203 mG (to tune for the same set of ions as in the first test) and a Bac range from 78 to 181 mG(rms). In all cases the observed responses were consistent with predictions of the IPR model. These experimental results are the first to support in detail the validity of the fundamental relationships embodied in the IPR model.

Clarification and application of an ion parametric resonance model for magnetic field interactions with biological systems.

Theoretical models proposed to date have been unable to clearly predict biological results from exposure to low-intensity electric and magnetic fields (EMF). Recently a predictive ionic resonance model was proposed by Lednev, based on an earlier atomic spectroscopy theory described by Podgoretskii and Podgoretskii and Khrustalev. The ion parametric resonance (IPR) model developed in this paper corrects mathematical errors in the earlier Lednev model and extends that model to give explicit predictions of biological responses to parallel AC and DC magnetic fields caused by field-induced changes in combinations of ions within the biological system. Distinct response forms predicted by the IPR model depend explicitly on the experimentally controlled variables: magnetic flux densities of the AC and DC magnetic fields (Bac and Bdc, respectively); AC frequency (fac); and, implicitly, charge to mass ratio of target-ions. After clarifying the IPR model and extending it to combinations of different resonant ions, this paper proposes a basic set of experiments to test the IPR model directly which do not rely on the choice of a particular specimen or endpoint. While the fundamental bases of the model are supported by a variety of other studies, the IPR model is necessarily heuristic when applied to biological systems, because it is based on the premise that the magnitude and form of magnetic field interactions with unhydrated resonant ions in critical biological structures alter ion-associated biological activities that may in turn be correlated with observable effects in living systems.