Biological effects of the hypomagnetic field: An analytical review of experiments and theories

Abstract

During interplanetary flights in the near future, a human organism will be exposed to prolonged periods of a hypomagnetic field that is 10,000 times weaker than that of Earth’s. Attenuation of the geomagnetic field occurs in buildings with steel walls and in buildings with steel reinforcement. It cannot be ruled out also that a zero magnetic field might be interesting in biomedical studies and therapy. Further research in the area of hypomagnetic field effects, as shown in this article, is capable of shedding light on a fundamental problem in biophysics—the problem of primary magnetoreception. This review contains, currently, the most extensive bibliography on the biological effects of hypomagnetic field. This includes both a review of known experimental results and the putative mechanisms of magnetoreception and their explanatory power with respect to the hypomagnetic field effects. We show that the measured correlations of the HMF effect with HMF magnitude and inhomogeneity and type and duration of exposure are statistically absent. This suggests that there is no general biophysical MF target similar for different organisms. This also suggests that magnetoreception is not necessarily associated with evolutionary developed specific magnetoreceptors in migrating animals and magnetotactic bacteria. Independently, there is nonspecific magnetoreception that is common for all organisms, manifests itself in very different biological observables as mostly random reactions, and is a result of MF interaction with magnetic moments at a physical level—moments that are present everywhere in macromolecules and proteins and can sometimes transfer the magnetic signal at the level of downstream biochemical events. The corresponding universal mechanism of magnetoreception that has been given further theoretical analysis allows one to determine the parameters of magnetic moments involved in magnetoreception—their gyromagnetic ratio and thermal relaxation time—and so to better understand the nature of MF targets in organisms.

Some recommendations for experimental work in magnetobiology, revisited

“…Further, because hypomagnetic field conditions allow for an assessment of bioeffects under near-zero field conditions, this can be taken as a standard of reference [Binhi and Prato, 2017b]. Interdisciplinary collaboration Seek collaboration between biologists and/or physicians, with engineers, and/or physicists.…”

“…of magnetobiology. Further, because hypomagnetic field conditions allow for an assessment of bioeffects under near-zero field conditions, this can be taken as a standard of reference [Binhi and Prato, 2017b]. All in all, it must be concluded that regardless of shielding the control samples (e.g., enclosing them in mu-metal containers) or not, what is crucial is to provide the full details of the fields at the location of controls/shams; it is impossible to replicate an experiment without complete knowledge of all MF components affecting the sham/control samples.…”

Geomagnetic field absence reduces adult body weight of a migratory insect by disrupting feeding behavior and appetite regulation

“…In a narrow sense, magnetoreception refers to the acute ability of animals to detect the GMF (Lohmann, 2010). However, increasing evidence for chronic responses of organisms to magnetic field variation suggests the importance of general magnetoreception in biological processes across taxa (Binhi and Prato, 2017;Henshaw et al, 2009;Maffei, 2014;Wan et al, 2016;Wan et al, 2014;Wan et al, 2015b;Wang et al, 2008). Among studies that subject organisms to different magnetic field intensity treatments, many concern the bioeffects induced by the near-zero magnetic field (NZMF) (Binhi and Prato, 2017;Wang et al, 2008).…”

“…However, increasing evidence for chronic responses of organisms to magnetic field variation suggests the importance of general magnetoreception in biological processes across taxa (Binhi and Prato, 2017;Henshaw et al, 2009;Maffei, 2014;Wan et al, 2016;Wan et al, 2014;Wan et al, 2015b;Wang et al, 2008). Among studies that subject organisms to different magnetic field intensity treatments, many concern the bioeffects induced by the near-zero magnetic field (NZMF) (Binhi and Prato, 2017;Wang et al, 2008). Although there may be the need for human beings to understand how organisms from Earth might perform during space travel where the field is ~10,000 times weaker than that of Earth's (Mallis and DeRoshia, 2005), the NZMF can also be taken as a sham control for the study of specific magnetoreception mechanisms (Fedele et al, 2014;Heyers et al, 2010).…”

Geomagnetic field intensity as a cue for the regulation of insect migration

“…However, few studies have focused on responses of animals to changes in geomagnetic field intensity at levels that naturally vary in their environment [12, 16]. Most studies of the bioeffects of GMF on organisms in the last decade have been conducted by either shielding or enhancing the GMF, and have highlighted its importance in maintaining homeostasis [13, 15, 17]. Our work with migratory white-backed planthopper, Sogatella furcifera , showed that the absence of GMF can affect the expression of important migration-related behaviours, potentially through Cry-mediated hormone signaling.…”