Weak extremely-low-frequency magnetic field-induced regeneration anomalies in the planarianDugesia tigrina

Abstract

We recently reported that cephalic regeneration in the planarian Dugesia tigrina was significantly delayed in populations exposed continuously to combined parallel DC and AC magnetic fields. This effect was consistent with hypotheses suggesting an underlying resonance phenomenon. We report here, in a parallel series of investigations on the same model system, that the incidence of regeneration anomalies presenting as tumor‐like protuberances also increases significantly (P < .001) in association with exposure to weak 60 Hz magnetic fields, with peak intensities ranging between 1.0 and 80.0 μT. These anomalies often culminate in the complete disaggregation of the organism. Similar to regeneration rate effects, the incidence of regeneration anomalies is specifically dependent upon the planaria possessing a fixed orientation with respect to the applied magnetic field vectors. However, unlike the regeneration rate effects, the AC magnetic field alone, in the absence of any measurable DC field, is capable of producing these anomalies. Moreover, the incidence of regeneration anomalies follows a clear dose‐response relationship as a function of AC magnetic field intensity, with the threshold for induced electric field intensity estimated at 5 μV/m. The addition of either 51.1 or 78.4 μT DC magnetic fields, applied in parallel combination with the AC field, enhances the appearance of anomalies relative to the 60 Hz AC field alone, but only at certain AC field intensities. Thus, whereas our previous study of regeneration rate effects appeared to involve exclusively resonance interactions, the regeneration anomalies reported here appear to result primarily from Faraday induction coupling. These results together with those reported previously point to two distinct physiological effects produced in regenerating planaria by exposure to weak extremely‐low‐frequency (ELF) magnetic fields. They further suggest that the planarian, which has recently been identified elsewhere as an excellent system for use in teratogenic investigations involving chemical teratogens, might be used similarly in teratogenic investigations involving ELF magnetic fields. © 1996 Wiley‐Liss, Inc.

Early exposure of rotating magnetic fields promotes central nervous regeneration in planarian Girardia sinensis

“…It was found that combined MFs produced a stimulating effect on reproduction and regeneration of planarians [Novikov et al, ]. However, combined MFs also led to regeneration anomalies [Jenrow et al, ]. In our study, RMFs (Fig.…”

“…Influence of MFs exposure on regeneration of planarians had been previously reported by Jenrow et al [] and Novikov et al []. In their studies, combined (weak static MF/alternating MF) collinear MFs were used for exposure.…”

Effects of large gradient high magnetic field (LG‐HMF) on the long‐term culture of aquatic organisms: Planarians example

“…In addition, a significantly higher rate of head regeneration was reported during exposure to a patterned electromagnetic field, resulting from the increasing number of biochemical pathways associated with cell proliferation, in particular, the p38-MAPK and hsp70 pathways [Tessaro and Persinger, 2013]. Furthermore, the weak ELF magnetic field was likely teratogenic in planarian head regeneration [Jenrow et al, 1996]. However, in this study, the results indicated that the high magnetic fields provided by the superconducting magnet had no lethal or teratogenic effect on planarian head regeneration, thus yielding the same conclusion that the strong static magnetic field was safe for living organisms [Yamaguchi-Sekino et al, 2011].…”

Advances in Electromagnetic Fields in Living Systems

“…Further complicating this picture, possibly, is Faraday's Law of Induction. Increasing the intensity of B will always cause larger induced currents, possibly leading to extra biological responses that are independent of those that are q/m-related [Jenrow et al 1996].…”