Magnetic field effects in biology from the perspective of the radical pair mechanism

Hundreds of studies have found that weak magnetic fields can significantly influence various biological systems. However, the underlying mechanisms behind these phenomena remain elusive. Remarkably, the magnetic energies implicated in these effects are much smaller than thermal energies. Here, we review these observations, and we suggest an explanation based on the radical pair mechanism, which involves the quantum dynamics of the electron and nuclear spins of transient radical molecules. While the radical pair mechanism has been studied in detail in the context of avian magnetoreception, the studies reviewed here show that magnetosensitivity is widespread throughout biology. We review magnetic field effects on various physiological functions, discussing static, hypomagnetic and oscillating magnetic fields, as well as isotope effects. We then review the radical pair mechanism as a potential unifying model for the described magnetic field effects, and we discuss plausible candidate molecules for the radical pairs. We review recent studies proposing that the radical pair mechanism provides explanations for isotope effects in xenon anaesthesia and lithium treatment of hyperactivity, magnetic field effects on the circadian clock, and hypomagnetic field effects on neurogenesis and microtubule assembly. We conclude by discussing future lines of investigation in this exciting new area of quantum biology.

How the Geomagnetic Field Influences Life on Earth - An Integrated Approach to Geomagnetobiology

Earth is one of the inner planets of the Solar System, but - unlike the others - it has an oxidising atmosphere, relatively stable temperature, and a constant geomagnetic field (GMF). The GMF does not only protect life on Earth against the solar wind and cosmic rays, but it also shields the atmosphere itself, thus creating relatively stable environmental conditions. What is more, the GMF could have influenced the origins of life: organisms from archaea to plants and animals may have been using the GMF as a source of spatial information since the very beginning. Although the GMF is constant, it does undergo various changes, some of which, e.g. a reversal of the poles, weaken the field significantly or even lead to its short-term disappearance. This may result in considerable climatic changes and an increased frequency of mutations caused by the solar wind and cosmic radiation. This review analyses data on the influence of the GMF on different aspects of life and it also presents current knowledge in the area. In conclusion, the GMF has a positive impact on living organisms, whereas a diminishing or disappearing GMF negatively affects living organisms. The influence of the GMF may also be an important factor determining both survival of terrestrial organisms outside Earth and the emergence of life on other planets.

Biological Effects of Hypomagnetic Field: Ground-Based Data for Space Exploration

The future of mankind is tied to the exploration and eventual colonization of space. Currently, people have resided in orbit at a space station. In the future, we will have opportunities to stay on the moon, Mars, or in deeper space, where astronauts are exposed to the hypomagnetic field (HMF), which refers to an extremely weak magnetic field environment compared with the geomagnetic field. However, the potential risks of HMF exposure to human health are often overlooked. Here, we summarize the literature related to the biological effects of HMF and calculate the magnitude of the effect. Briefly, HMF impairs multiple animal systems, especially in the central nervous system. Additionally, HMF is a stress factor in plant growth and reproduction. Finally, HMF combined with other space environments, such as radiation and microgravity, can affect organisms. Further studies are required to explore (i) countermeasures to the adverse effects of HMF, (ii) combined effects of HMF with other factors, and (iii) the intensity-effect relationship. © 2021 Bioelectromagnetics Society.

Biological Effects of Space Hypomagnetic Environment on Circadian Rhythm

The intrinsic earth magnetic field (geomagnetic field, GMF) provides an essential environmental condition for most living organisms to adapt the solar cycle by rhythmically synchronizing physiological and behavioral processes. However, hypomagnetic field (HMF) of outer space, the Moon, and the Mars differs much from GMF, which poses a critical problem to astronauts during long-term interplanetary missions. Multiple experimental works have been devoted to the HMF effects on circadian rhythm and found that HMF perturbs circadian rhythms and profoundly contributes to health problems such as sleep disorders, altered metabolic as well as neurological diseases. By systemizing the latest progress on interdisciplinary cooperation between magnetobiology and chronobiology, this review sheds light on the health effects of HMF on circadian rhythms by elaborating the underlying circadian clock machinery and molecular processes.

Tolerance of two anhydrobiotic tardigrades Echiniscus testudo and Milnesium inceptum to hypomagnetic conditions

The open space is a hostile environment for all lifeforms not only due to vacuum, high radiation, low atmospheric pressure, and extremely low temperature, but also the absence of the geomagnetic field. The geomagnetic field protects Earth mainly from corpuscular radiation, that is, solar wind and cosmic radiation, but above all it influences organisms, including their cells, tissues and organs. Moreover, numerous studies conducted on plants and animals confirmed that hypomagnetic conditions (the term referring to all situations when the magnetic field is weaker than the typical geomagnetic field) have significant influence on the metabolism of living organisms. Although many studies dealt with a variety of aspects related mainly to the influence of hypomagnetic conditions on human health. Very few studies have considered the influence of hypomagnetic conditions on extremophiles. Astrobiologists have long been testing different extremofiles to find out if any multicellular organisms are able to survive in extreme conditions of open space. Among all multicellular extremophiles fit for such research, water bears (Tardigrada) are the most interesting. Not only are they one of the most resistant organisms on Earth, but results obtained from studies on these invertebrates can be extrapolated or applied to vertebrates (including humans). Despite this, studies on the influence of hypomagnetic conditions on tardigrades are rare, so far. In the present study, to test the influence of hypomagnetic conditions on the process of anhydrobiosis while entering and returning from anhydrobiosis, we used two terrestrial anhydrobiotic species that are Echiniscus testudo and Milnesium inceptum. To exclude the ambient magnetic field, experiments were carried out in a special magnetic field shielding chamber. In total, three experiments were conducted: (a) tardigrades in anhydrobiosis, (b) tardigrades entering anhydrobiosis and (c) tardigrades returning to active life. The obtained results clearly showed that even partial isolation from the geomagnetic field, that is, hypomagnetic conditions, has negative influence on anhydrobiotic abilities of both tested tardigrade species. In both species we observed lower survivability rate while entering anhydrobiosis, in anhydrobiotic state and returning to the active state. What is more, we observed a higher mortality rate in Ech. testudo than Mil. inceptum which suggest that different species response to the hypomagnetic conditions in different way. In conclusion, while current knowledge on the influence of hypomagnetic conditions on mortality of invertebrates is very limited, our results suggest that the presence of the magnetic field is a very important factor which should be considered in further research focused on potential survival of Earth organisms in outer space, spacecrafts or different planets and moons.

Reactive Oxygen Species: Potential Regulatory Molecules in Response to Hypomagnetic Field Exposure

Organisms, including humans, could be exposed to hypomagnetic fields (HMFs, intensity <5 μT), e.g. in some artificially shielded magnetic environments and during deep-space flights. Previous studies have demonstrated that HMF exposure could have negative effects on the central nervous system and embryonic development in many animals. However, the underlying mechanisms remain unknown. Studies have revealed that HMFs affect cellular reactive oxygen species (ROS) levels and thereby alter physiological and biological processes in organisms. ROS, the major component of highly active free radicals, which are ubiquitous in biological systems, were hypothesized to be the candidate signaling molecules that regulate diverse physiological processes in response to changes in magnetic fields. Here, we summarize the recent advances in the study of HMF-induced negative effects on the central nervous system and early embryonic development in animals, focusing on cellular ROS and their role in response to HMFs. Furthermore, we discuss the potential mechanism through which HMFs regulate ROS levels in cells. © 2020 Bioelectromagnetics Society.

Basic concepts and physical-chemical phenomena, that have conceptual meaning for the formation of systemic clinical thinking and formalization of the knowledge of systemic structural-functional organization of the human’s organism

From the point of view of perception and generalization processes there are complex, logic and conceptual forms of thinking. Its conceptual form is the highest result of interaction between thinking and speech. While realizing it, human uses the concept, which are logically formed thoughts, that are the meaning of representation in thinking of unity of meaningful features, relations of subjects or phenomena of objective reality. Special concepts, that are used in the science and technique are called terms. They perform a function of corresponding, special, precise marking of subjects and phenomena, their features and interactions. Scientific knowledge are in that way an objective representation of material duality in our consciousness. Certain complex of terms forms a terminological system, that lies in the basis of corresponding sphere of scientific knowledge and conditions a corresponding form and way of thinking. Clinical thinking is a conceptual form, that manifests and represents by the specialized internal speech with gnostic motivation lying in its basis. Its structural elements are corresponding definitions, terms and concepts. Cardinal features of clinical systems are consistency, criticality, justification and substantiation. Principles of perception and main concepts are represented in the article along with short descriptions of physical and chemical phenomena, that have conceptual meaning for the formation of systematic clinical thinking and formalization of systemic structural-functional organization of the human’s organism

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

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.