Magnetic material in the human hippocampus

doi:10.1016/0361-9230(94)00182-Z

Brain Research Bulletin

Volume 36, Issue 2, 1995, Pages 149-153

https://doi.org/10.1016/0361-9230(94)00182-Z Get rights and content

Abstract

Magnetic analyses of hippocampal material from deceased normal and epileptic subjects, and from the surgically removed epileptogenic zone of a living patient have been carried out. All had magnetic characteristics similar to those reported for other parts of the brain [6]. These characteristics along with low temperature analysis indicate that the magnetic material is present in a wide range of grain sizes. The low temperature analysis also revealed the presence of magnetite through manifestation of its low temperature transition. The wide range of grain sizes is similar to magnetite produced extracellularly by the GS15 strain of bacteria and unlike that found in magnetotactic bacteria MV-1, which has a restricted grain size range. Optical microscopy of slices revealed rare 5–10 micron clusters of finer opaque particles, which were demonstrated with Magnetic Force Microscopy to be magnetic. One of these was shown with EDAX to contain All, Ca, Fe, and K, with approximate weight percentages of 55, 19, 19, and 5, respectively.

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The high magnetic moment of magnetite as compared to ferrihydrite (found in physiological ferritin) makes it an attractive material for MFM studies. Along these lines, in an earlier report, MFM signals were detected on very thick sections of the epileptic brain, which had been previously characterized for magnetic material via isothermal remnant magnetization [36]. We could not detect iron via Perls staining in our AD samples, indicating that iron is heterogeneously distributed in the AD brain.
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Why electrohypersensitivity and related symptoms are caused by non-ionizing man-made electromagnetic fields: An overview and medical assessment
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due to the presence of electromagnetic receptors, as in bacteria and many animals, humans are all sensitive to EMFs, but normally not hypersensitive. Such receptors have been identified as “cryptochroms” in animal retina (Gegear et al., 2010; Grehl et al., 2016) and as “magnetosomes” in the human brain (particularly in the hippocampus) and in the meninges (Kirschvink et al., 1992a; Dunn et al., 1995; Maher et al., 2016). Magnetosomes are located mainly in areas thought to correspond to the observed EHS-associated pathophysiological abnormalities and clinical symptoms (hippocampus and meninges) in EHS patients.
Much of the controversy over the cause of electrohypersensitivity (EHS) lies in the absence of recognized clinical and biological criteria for a widely accepted diagnosis. However, there are presently sufficient data for EHS to be acknowledged as a distinctly well-defined and objectively characterized neurologic pathological disorder. Because we have shown that 1) EHS is frequently associated with multiple chemical sensitivity (MCS) in EHS patients, and 2) that both individualized disorders share a common pathophysiological mechanism for symptom occurrence; it appears that EHS and MCS can be identified as a unique neurologic syndrome, regardless their causal origin. In this overview we distinguish the etiology of EHS itself from the environmental causes that trigger pathophysiological changes and clinical symptoms after EHS has occurred. Contrary to present scientifically unfounded claims, we indubitably refute the hypothesis of a nocebo effect to explain the genesis of EHS and its presentation. We as well refute the erroneous concept that EHS could be reduced to a vague and unproven “functional impairment”. To the contrary, we show here there are objective pathophysiological changes and health effects induced by electromagnetic field (EMF) exposure in EHS patients and most of all in healthy subjects, meaning that excessive non-thermal anthropogenic EMFs are strongly noxious for health. In this overview and medical assessment we focus on the effects of extremely low frequencies, wireless communications radiofrequencies and microwaves EMF. We discuss how to better define and characterize EHS. Taken into consideration the WHO proposed causality criteria, we show that EHS is in fact causally associated with increased exposure to man-made EMF, and in some cases to marketed environmental chemicals. We therefore appeal to all governments and international health institutions, particularly the WHO, to urgently consider the growing EHS-associated pandemic plague, and to acknowledge EHS as a mainly new real EMF causally-related pathology.
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Evaluation of iron distribution and density in biological tissues is important to understand the pathogenesis of a variety of diseases and the fate of exogenously administered iron-based carriers and contrast agents. Iron distribution in tissues is typically characterized via histochemical (Perl's) stains or immunohistochemistry for ferritin, the major iron storage protein. A more accurate mapping of iron can be achieved via ultrastructural transmission electron microscopy (TEM) based techniques, which involve stringent sample preparation conditions. In this study, we elucidate the capability of magnetic force microscopy (MFM) as a label-free technique to map iron at the nanoscale level in rodent spleen tissue. We complemented and compared our MFM results with those obtained using Perl's staining and TEM. Our results show how MFM mapping corresponded to sizes of iron-rich lysosomes at a resolution comparable to that of TEM. In addition MFM is compatible with tissue sections commonly prepared for routine histology.
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Specialized studies in the field of rock magnetism using ultrasensitive superconducting quantum-interference device magnetometers (SQUIDS) in clean-lab environments can detect picogram quantities of single-domain magnetite in gram-size tissue samples [47]. Standard rock-magnetic techniques demonstrate that most of these particles are dispersed in isolated particles or small clumps [8,9,19,23], rather than in the concentrated aggregates like the chiton teeth [21]. Typical concentrations of magnetite in animal tissues inferred from these studies range from 1 to 100 ng/g, with particle sizes in the 10–100 nm size range where they have been extracted and examined with high-resolution TEM [19,25,33].
An outstanding biophysical puzzle is focused on the apparent ability of weak, extremely low-frequency oscillating magnetic fields to enhance cryopreservation of many biological tissues. A recent theory holds that these weak magnetic fields could be inhibiting ice-crystal nucleation on the nanocrystals of biological magnetite (Fe₃O₄, an inverse cubic spinel) that are present in many plant and animal tissues by causing them to oscillate. In this theory, magnetically-induced mechanical oscillations disrupt the ability of water molecules to nucleate on the surface of the magnetite nanocrystals. However, the ability of the magnetite crystal lattice to serve as a template for heterogeneous ice crystal nucleation is as yet unknown, particularly for particles in the 10–100 nm size range. Here we report that the addition of trace-amounts of finely-dispersed magnetite into ultrapure water samples reduces strongly the incidence of supercooling, as measured in experiments conducted using a controlled freezing apparatus with multiple thermocouples. SQUID magnetometry was used to quantify nanogram levels of magnetite in the water samples. We also report a relationship between the volume change of ice, and the degree of supercooling, that may indicate lower degassing during the crystallization of supercooled water. In addition to supporting the role of ice-crystal nucleation by biogenic magnetite in many tissues, magnetite nanocrystals could provide inexpensive, non-toxic, and non-pathogenic ice nucleating agents needed in a variety of industrial processes, as well as influencing the dynamics of ice crystal nucleation in many natural environments.
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2015, Journal of Magnetism and Magnetic Materials
Citation Excerpt :
The main aim of the presented study was to see a transfer of iron from exogenous nanoparticles to any endogenous form of iron. There are many endogenous iron phases in the brain tissue, which include heme iron, different forms of ferritin and hemosiderine, magnetite, maghemite and even wustite [22–28]. The first histochemical study of the iron concentration distribution in the brain was fulfilled by Spatz [29] almost one hundred years ago using Perl's stanning method.
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Recent discussions in the literature have questioned the ability of electromagnetic exposure to inhibit ice crystal formation in supercooled water. Here we note that strong electric fields are able to disrupt the surface boundary layer of inert air on the surface of materials, promoting higher rates of heat transport. We also note that most biological tissues contain ferromagnetic materials, both biologically precipitated magnetite (Fe₃O₄) as well as environmental contaminants that get accidentally incorporated into living systems. Although present at trace levels, the number density of these particulates is high, and they have extraordinarily strong interactions with weak, low-frequency magnetic fields of the sort involved in claims of electromagnetic cryopreservation. Magnetically-induced mechanical oscillation of these particles provides a plausible mechanism for the disruption of ice-crystal nucleation in supercooled water.

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ArticleMagnetic material in the human hippocampus

Abstract

Phys. Earth Planet. Inter.

Brain Res. Bull.

Giving personal magnetism a whole new meaning

Science

Stability of anhysteretic magnetization in fine and coarse grained magnetite and maghemite particles

Geophys. J. Royal Astron. Soc.

Magnetite biomineralization in the human brain

Chaotic activity during iron-induced “pileptiform” discharge in rat hippocampal slices

IEEE Trans. on Biomed. Eng.

Article
Magnetic material in the human hippocampus