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EMF Studies

10 August 2017

Sixteen New Papers on Electromagnetic Fields and Biology or Health (8 August 2017)

Sixteen new papers on electromagnetic fields and biology or health, courtesy of Joel M. Moskowitz, Ph.D., Director, Center for Family and Community Health, School of Public Health, University of California, Berkeley.
Electromagnetic Radiation Safety, August 8, 2017


Impact of RFR on DNA damage & antioxidants in peripheral blood lymphocytes of humans residing in the vicinity of mobile phone base stations

Zothansiama, Zosangzuali M, Lalramdinpuii M, Jagetia GC. Impact of radiofrequency radiation on DNA damage and antioxidants in peripheral blood lymphocytes of humans residing in the vicinity of mobile phone base stations. Electromagn Biol Med. 2017 Aug 4:1-11. doi: 10.1080/15368378.2017.1350584.

Abstract



Radiofrequency radiations (RFRs) emitted by mobile phone base stations have raised concerns on its adverse impact on humans residing in the vicinity of mobile phone base stations. Therefore, the present study was envisaged to evaluate the effect of RFR on the DNA damage and antioxidant status in cultured human peripheral blood lymphocytes (HPBLs) of individuals residing in the vicinity of mobile phone base stations and comparing it with healthy controls.
The study groups matched for various demographic data including age, gender, dietary pattern, smoking habit, alcohol consumption, duration of mobile phone use and average daily mobile phone use.

The RF power density of the exposed individuals was significantly higher (p < 0.0001) when compared to the control group. The HPBLs were cultured and the DNA damage was assessed by cytokinesis blocked micronucleus (MN) assay in the binucleate lymphocytes. The analyses of data from the exposed group (n = 40), residing within a perimeter of 80 meters of mobile base stations, showed significantly (p < 0.0001) higher frequency of micronuclei (MN) when compared to the control group, residing 300 meters away from the mobile base station/s.

The analysis of various antioxidants in the plasma of exposed individuals revealed a significant attrition in glutathione (GSH) concentration (p < 0.01), activities of catalase (CAT) (p < 0.001) and superoxide dismutase (SOD) (p < 0.001) and rise in lipid peroxidation (LOO) when compared to controls. Multiple linear regression analyses revealed a significant association among reduced GSH concentration (p < 0.05), CAT (p < 0.001) and SOD (p < 0.001) activities and elevated MN frequency (p < 0.001) and LOO (p < 0.001) with increasing RF power density.

https://www.ncbi.nlm.nih.gov/pubmed/28777669

My note: All of the recorded RFR power density values in this study were well below the Federal Communication Commission’s maximum permissible exposure limits in the U.S. for the general population. These limits are are 6,000 mW/m2 [milliwatts per square meter] for 900 MHz and 10,000 mW/m2 for 1800 MHz radiofrequency radiation. In contrast, the highest recorded value in this study was 7.52 mW/m2 of RFR. The “exposed individuals” who resided within 80 meters of a cell antenna received an average of 5.00 mW/m2 of RFR in their bedrooms.

To see excerpts from this study and related research: Cell Tower Health Effects or http://bit.ly/saferemrcelltower

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Mobile phone RF exposure has no effect on DNA double strand breaks in human lymphocytes

Danese E, Lippi G, Buonocore R, Benati M, Bovo C, Bonaguri C, Salvagno GL, Brocco G, Roggenbuck D, Montagnana M. Mobile phone radiofrequency exposure has no effect on DNA double strand breaks (DSB) in human lymphocytes. Ann Transl Med. 2017 Jul;5(13):272. doi: 10.21037/atm.2017.04.35.

Abstract

BACKGROUND: The use of mobile phones has been associated with an increased risk of developing certain type of cancer, especially in long term users. Therefore, this study was aimed to investigate the potential genotoxic effect of mobile phone radiofrequency exposure on human peripheral blood mononuclear cells in vitro.

METHODS: The study population consisted in 14 healthy volunteers. After collection of two whole blood samples, the former was placed in a plastic rack, 1 cm from the chassis of a commercial mobile phone (900 MHz carrier frequency), which was activated by a 30-min call. The second blood sample was instead maintained far from mobile phones or other RF sources. The influence of mobile phone RF on DNA integrity was assessed by analyzing γ-H2AX foci in lymphocytes using immunofluorescence staining kit on AKLIDES.

RESULTS: No measure of γ-H2AX foci was significantly influenced by mobile phone RF exposure, nor mobile phone exposure was associated with significant risk of genetic damages in vitro (odds ratio comprised between 0.27 and 1.00).

CONCLUSIONS: The results of this experimental study demonstrate that exposure of human lymphocytes to a conventional 900 MHz RF emitted by a commercial mobile phone for 30 min does not significantly impact DNA integrity.

https://www.ncbi.nlm.nih.gov/pubmed/28758098

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Effects of Long-Term Exposure to 60 GHz Millimeter-Wavelength Radiation on Genotoxicity & Heat Shock Protein Expression of Cells Derived from Human Eye

Koyama S, Narita E, Shimizu Y, Suzuki Y, Shiina T, Taki M, Shinohara N, Miyakoshi J.Effects of Long-Term Exposure to 60 GHz Millimeter-Wavelength Radiation on the Genotoxicity and Heat Shock Protein (Hsp) Expression of Cells Derived from Human Eye. Int J Environ Res Public Health. 2016 Aug 8;13(8). pii: E802. doi: 10.3390/ijerph13080802.

Abstract

Human corneal epithelial (HCE-T) and human lens epithelial (SRA01/04) cells derived from the human eye were exposed to 60 gigahertz (GHz) millimeter-wavelength radiation for 24 h. There was no statistically significant increase in the micronucleus (MN) frequency in cells exposed to 60 GHz millimeter-wavelength radiation at 1 mW/cm² compared with sham-exposed controls and incubator controls. The MN frequency of cells treated with bleomycin for 1 h provided positive controls. The comet assay, used to detect DNA strand breaks, and heat shock protein (Hsp) expression also showed no statistically significant effects of exposure. These results indicate that exposure to millimeter-wavelength radiation has no effect on genotoxicity in human eye cells.

https://www.ncbi.nlm.nih.gov/pubmed/27509516

Related Posts:
5G Wireless Technology: Millimeter Wave Health Effects

5G Wireless Technology: Is 5G Harmful to Our Health?

5G Wireless Technology: Major newspaper editorials oppose "small cell" antenna bills

Cell Tower Health Effects
Electromagnetic Hypersensitivity

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RF EMF exposure in everyday microenvironments in Europe: A systematic literature review

Sagar S, Dongus S, Schoeni A, Roser K, Eeftens M, Struchen B, Foerster M, Meier N, Adem S, Röösli M. Radiofrequency electromagnetic field exposure in everyday microenvironments in Europe: A systematic literature review. J Expo Sci Environ Epidemiol. 2017 Aug 2. doi: 10.1038/jes.2017.13.

Abstract

The impact of the introduction and advancement in communication technology in recent years on exposure level of the population is largely unknown. The main aim of this study is to systematically review literature on the distribution of radiofrequency electromagnetic field (RF-EMF) exposure in the everyday environment in Europe and summarize key characteristics of various types of RF-EMF studies conducted in the European countries.

We systematically searched the ISI Web of Science for relevant literature published between 1 January 2000 and 30 April 2015, which assessed RF-EMF exposure levels by any of the methods: spot measurements, personal measurement with trained researchers and personal measurement with volunteers.

Twenty-one published studies met our eligibility criteria of which 10 were spot measurements studies, 5 were personal measurement studies with trained researchers (microenvironmental), 5 were personal measurement studies with volunteers and 1 was a mixed methods study combining data collected by volunteers and trained researchers. RF-EMF data included in the studies were collected between 2005 and 2013. The mean total RF-EMF exposure for spot measurements in European "Homes" and "Outdoor" microenvironments was 0.29 and 0.54 V/m, respectively. In the personal measurements studies with trained researchers, the mean total RF-EMF exposure was 0.24 V/m in "Home" and 0.76 V/m in "Outdoor". In the personal measurement studies with volunteers, the population weighted mean total RF-EMF exposure was 0.16 V/m in "Homes" and 0.20 V/m in "Outdoor". Among all European microenvironments in "Transportation", the highest mean total RF-EMF 1.96 V/m was found in trains of Belgium during 2007 where more than 95% of exposure was contributed by uplink.

Typical RF-EMF exposure levels are substantially below regulatory limits. We found considerable differences between studies according to the type of measurements procedures, which precludes cross-country comparison or evaluating temporal trends. A comparable RF-EMF monitoring concept is needed to accurately identify typical RF-EMF exposure levels in the everyday environment.

https://www.ncbi.nlm.nih.gov/pubmed/28766560

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Measurement of the environmental broadband electromagnetic waves in a mid-size European city

Fernández-García R, Gil I. Measurement of the environmental broadband electromagnetic waves in a mid-size European city. Environ Res. 2017 Jul 26;158:768-772. doi: 10.1016/j.envres.2017.07.040.

Abstract

In this paper, the level of exposure to broadband radiofrequency electromagnetic field in a mid-size European city was evaluated in accordance with the International Commission on Non-ionizing Radiation Protection guidelines from 1998. With the aim to analyse all the potential electromagnetic waves present in the city up to 18GHz, a total of 271 locations distributed along Terrassa (Spain) have been measured. To show the results in an easy-to-interpret way by the citizen, the results have been represented in a set of raster maps. The measurement results obtained showed that the electromagnetic wave measured in all broadband frequency range along the city is much lower than the safety level according to the international regulations for both public and occupational sectors.

https://www.ncbi.nlm.nih.gov/pubmed/28755561

Excerpts

... according to the World Health Organization, due to the ubiquitous source of RF radiation the percentage of all people being exposed to RF electromagnetic radiation is rapidly approaching the percentage exposed to polluted air (Lin, 2016) and therefore, more research must be devoted to this crucial issue. In addition, it is necessary to extend the RF-EMF exposure assessment to broadband frequency measurements including fields beyond 6 GHz. This fact will be mandatory in the future because of the deployment of new wirelessstandards such as the fifth-generation mobile communication systems (5G) (Colombi et al., 2015; Zhao et al., 2015).

The electric field measurements have been carried out by means of the electromagnetic field meter Wavecontrol SMP2 and a WPF18broadband isotropic probe to assess the radioelectric environment and all the potential hand-made radiofrequency sources. The probe has a broadband frequency range from 300 kHz to 18 GHz with a measurement range from 0.5 V/m to 250 V/m. The electromagnetic sensor is based on a diode technology and it presents a sensitivity of 0.5 V/m with a resolution lower than 5%, a dynamic range of 54 dB and a linearity of ± 0.5 dB. The measurement equipment has been calibrated according to the ISO 17025 standard. The equipment is able to cover all the potential non-ionizing electromagnetic emissions in the environment from 300 kHz to 18 GHz....


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Are electromagnetic fields in incubators a risk factor for autism?

Bellieni CV, Buonocore G. Acta Paediatr. Are electromagnetic fields in incubators a risk factor for autism? 2017 Jul 22. doi: 10.1111/apa.14001.

Abstract

Hugo Lagercrantz recently argued (1) that a possible cause of infantile autism was the unnatural isolation that babies experienced in neonatal incubators. Atypical brain connectivity has been detected in children with autism and it is possible that this may be also due to environmental factors, including the lack of physiological stimuli that is typically found in the incubator environment. We suggest that also another factor may expose babies in incubators to the risk of developing autistic traits and that is the high electromagnetic fields (EMF) produced by the incubator's electric engine.

https://www.ncbi.nlm.nih.gov/pubmed/28734102

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Report from the BioEM2017: Annual meeting of BEMS & EBEA

Dariusz Leszczynski. Report from the BioEM2017: Annual meeting of BEMS & EBEA, Hangzhou, China, June 5-9, 2017.

https://betweenrockandhardplace.files.wordpress.com/2017/07/report-from-bioem2017.pdf

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Effects of short and long term EMF exposure on the human hippocampus

Omur Gulsum Deniz, Suleyman Kaplan, Mustafa Bekir Selçuk, Murat Terzi, Gamze Altun, Kıymet Kübra Yurt, Kerim Aslan, Devra Davis. Effects of short and long term electromagnetic fields exposure on the human hippocampus. Journal of Microscopy and Ultrastructure, In Press, Corrected Proof, Available online 13 July 2017.

Highlights

• This pilot investigation of female medical students finds that electromagnetic fields exposure does not alter the volume of the human hippocampus.
• Widespread use of mobile phones among medical students results in a low level of concentration in the present study.
• Prolonged use of mobile phones can lead to a decline in the ability to suppress stimuli.

Abstract

The increasing use of mobile phones may have a number of physiological and psychological effects on human health. Many animal and human studies have reported various effects on the central nervous system and cognitive performance from of exposure to electromagnetic fields (EMF) emitted by mobile phones. The aim of the present study was to evaluate the effects of mobile phones on the morphology of the human brain and on cognitive performance using stereological and spectroscopic methods and neurocognitive tests.

Sixty healthy female medical school students aged 18–25 years were divided into a low exposure group (30 subjects, <30 min daily use by the head) and high exposure group (30 subjects, >90 min daily use by the head). Magnetic resonance images (MRI) of the brain analysed on OsiriX 3.2.1 workstation. Neuropsychological tests were performed for each subject. In addition, three dominant specific metabolites were analysed, choline at 3.21 ppm, creatine at 3.04 ppm and N-acetyl aspartate at 2.02 ppm. Analysis of the spectroscopic results revealed no significant difference in specific metabolites between the groups (p > 0.05). There was also no significant difference in terms of hippocampal volume between the groups (p > 0.05). In contrast, the results of the stroop and digit span (backward) neurocognitive tests of high exposure group for evaluating attention were significantly poorer from low exposure group (p < 0.05). Based on these results, we conclude that a lack of attention and concentration may occur in subjects who talk on mobile phones for longer times, compared to those who use phones relatively less.

http://www.sciencedirect.com/science/article/pii/S2213879X17300524

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Monte Carlo simulations of skin exposure to electromagnetic field from 10 GHz to 1 THz

Sasaki K, Mizuno M, Wake K, Watanabe S. Monte Carlo simulations of skin exposure to electromagnetic field from 10 GHz to 1 THz.
Phys Med Biol. 2017 Jul 25. doi: 10.1088/1361-6560/aa81fc.

Abstract

In this study, we present an assessment of human-body exposure to an electromagnetic eld at frequencies ranging from 10 GHz to 1 THz. The energy absorption and temperature elevation were assessed by solving boundary value problems of the one-dimensional Maxwell equations and a bioheat equation for a multilayer plane model. Dielectric properties were measured in vitro at frequencies of up to 1 THz at body temperature. A Monte Carlo simulation was conducted to assess variations of the transmittance into a skin surface and temperature elevation inside a body by considering the variation of the tissue thickness due to individual differences among human bodies. Furthermore, the impact of the dielectric properties of adipose tissue on temperature elevation, for which large discrepancies between our present measurement results and those in past works were observed, was also examined. We found that the dielectric properties of adipose tissue do not impact on temperature elevation at frequencies over 30 GHz. The potential risk of skin burn was discussed on the basis of the temperature elevation in millimeter-wave and terahertz-wave exposure. Furthermore, the consistency of the basic restrictions in the international guidelines set by ICNIRP was discussed.

https://www.ncbi.nlm.nih.gov/pubmed/28742056

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Electromagnetic fields may act via calcineurin inhibition to suppress immunity, thereby increasing risk for opportunistic infection: Conceivable mechanisms of action

Doyon, PR, Johansson O. Electromagnetic fields may act via calcineurin inhibition to suppress immunity, thereby increasing risk for opportunistic infection: Conceivable mechanisms of action. Med Hypotheses. 106:71-87. Sep 2017. https://doi.org/10.1016/j.mehy.2017.06.028Get rights and content

Abstract

While a good number of studies have demonstrated that modern, man-made ambient electromagnetic fields can have both stimulatory and inhibitory effect on immune system function, the precise mechanisms have yet to be completely elucidated. It is hypothesized here that, depending on the parameters, one of the means by which long-term electromagnetic field exposure has the potential to eventually lead to immunosuppression is via downstream inhibition of the enzyme calcineurin — a protein phosphatase, which activates the T-cells of the immune system and can be blocked by pharmaceutical agents.

Calcineurin is the target of a class of pharmaceuticals called calcineurin inhibitors (e.g., cyclosporine, pimecrolimus and tacrolimus). When organ transplant recipients take such pharmaceuticals to prevent or suppress organ transplant rejection, one of the major side effects is immunosuppression leading to increased risk of opportunistic infection: e.g., fungal, viral (Epstein-Barr virus, cytomegalovirus), atypical bacterial (Nocardia, Listeria, mycobacterial, mycoplasma), and parasitic (e.g., toxoplasmosis) infections.

Frequent anecdotal reports, as well as a number of scientific studies, have shown that electromagnetic field exposures may indeed produce the same effect: a weakened immune system leading to an increase in the same or similar opportunistic infections: i.e., fungal, viral, atypical bacterial, and parasitic infections.

Furthermore, numerous research studies have shown that man-made electromagnetic fields have the potential to open voltage-gated calcium channels, which can in turn produce a pathological increase of intracellular calcium, leading downstream to the pathological production of a series of reactive oxygen species. Finally, there are a number of research studies demonstrating the inhibition of calcineurin by a pathological production of reactive oxygen species.

Hence, it is hypothesized here that exposures to electromagnetic fields have the potential to inhibit immune system response by means of an eventual pathological increase in the influx of calcium into the cytoplasm of the cell, which induces a pathological production of reactive oxygen species, which in turn can have an inhibitory effect on calcineurin. Calcineurin inhibition leads to immunosuppression, which in turn leads to a weakened immune system and an increase in opportunistic infection.

http://www.sciencedirect.com/science/article/pii/S0306987717301718

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Biochemical & pathological changes in male rat kidney & bladder following exposure to continuous 900-MHz EMF on postnatal days 22-59

Türedi S, Kerimoğlu G, Mercantepe T, Odacı E. Biochemical and pathological changes in the male rat kidney and bladder following exposure to continuous 900-MHz electromagnetic field on postnatal days 22-59. Int J Radiat Biol. 2017 Jul 27:1-10. doi: 10.1080/09553002.2017.1350768.

Abstract

PURPOSE: To investigate the effect on male rat kidney and bladder tissues of exposure to 900-megahertz (MHz) electromagnetic field (EMF) applied on postnatal days 22-59, inclusive.

MATERIALS AND METHODS: Twenty-four male Sprague Dawley rats, aged 21 days, were used. These were divided equally into one of three groups, control (CG), sham (SG) or EMF (EMFG). CG was not exposed to any procedure. SG rats were kept inside a cage, without being exposed to the effect of EMF, for 1 h a day on postnatal days 22-59, inclusive. EMFG rats were exposed to continuous 900-MHz EMF for 1 h a day under the same conditions as those for the SG rats. Rats were sacrificed on postnatal day 60, and the kidney and bladder tissues were removed. Tissues were stained with hematoxylin and eosin (H&E) and Masson trichrome for histomorphological evaluation. The TUNEL method was used to assess apoptosis. Transmission electron microscopy (TEM) was also used for the kidney tissue. Oxidant/antioxidant parameters were studied in terms of biochemical values.

RESULTS: The findings showed that tissue malondialdehyde increased in EMFG compared to CG and SG in both kidney (p = 0.004 and p = 0.004, respectively) and bladder tissue (p = 0.004, p = 0.006, respectively), while catalase and glutathione levels decreased compared to CG (p = 0.004; p = 0.004, respectively) and SG (p = 0.004; p = 0.004, respectively). In the EMF group, pathologies such as dilatation and vacuolization in the distal and proximal tubules, degeneration in glomeruli and an increase in cells tending to apoptosis were observed in kidney tissue. In bladder tissue, degeneration in the transitional epithelium and stromal irregularity and an increase in cells tending to apoptosis were observed in EMFG. Additionally, EMFG samples exhibited glomerular capillary degeneration with capillary basement membranes under TEM.

CONCLUSIONS: We conclude that continuous exposure to the effect of 900-MHz EMF for 1 h a day on postnatal days 22-59, inclusive, causes an increase in oxidative stress and various pathological changes in male rat kidney and bladder tissues.

https://www.ncbi.nlm.nih.gov/pubmed/28747141

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Anxiety-like behavioural effects of ELF EMF in rats

Djordjevic NZ, Paunović MG, Peulić AS.Anxiety-like behavioural effects of extremely low-frequency electromagnetic field in rats. Environ Sci Pollut Res Int. 2017 Jul 29. doi: 10.1007/s11356-017-9710-1.

Abstract

In recent years, extremely low-frequency electromagnetic field (ELF-EMF) has received considerable attention for its potential biological effects. Numerous studies have shown the role of ELF-EMF in behaviour modulation. The aim of this study was to investigate the effect of short-term ELF-EMF (50 Hz) in the development of anxiety-like behaviour in rats through change hypothalamic oxidative stress and NO. Ten adult male rats (Wistar albino) were divided in two groups: control group-without exposure to ELF-EMF and experimental group-exposed to ELF-EMF during 7 days. After the exposure, time open field test and elevated plus maze were used to evaluate the anxiety-like behaviour of rats. Upon completion of the behavioural tests, concentrations of superoxide anion (O2·-), nitrite (NO2-, as an indicator of NO) and peroxynitrite (ONOO-) were determined in the hypothalamus of the animals. Obtained results show that ELF-EMF both induces anxiety-like behaviour and increases concentrations of O2·- and NO, whereas it did not effect on ONOO- concentration in hypothalamus of rats. In conclusion, the development of anxiety-like behaviour is mediated by oxidative stress and increased NO concentration in hypothalamus of rats exposed to ELF-EMF during 7 days.

https://www.ncbi.nlm.nih.gov/pubmed/28756602

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Influence of electromagnetic pulse on the offspring sex ratio of male BALB/c mice

Li JH, Jiang DP, Wang YF, Yan JJ, Guo QY, Miao X, Lang HY, Xu SL, Liu JY, Guo GZ.Influence of electromagnetic pulse on the offspring sex ratio of male BALB/c mice. Environ Toxicol Pharmacol. 2017 Jun 21;54:155-161. doi: 10.1016/j.etap.2017.06.015. [Epub ahead of print]

Abstract

Public concern is growing about the exposure to electromagnetic fields (EMF) and its effect on male reproductive health. Detrimental effect of EMF exposure on sex hormones, reproductive performance and sex-ratio was reported. The present study was designed to clarify whether paternal exposure to electromagnetic pulse (EMP) affects offspring sex ratio in mice. 50 male BALB/c mice aged 5-6 weeks were exposed to EMP daily for 2 weeks before mated with non-exposed females at 0d, 7d, 14d, 21d and 28d after exposure. Sex hormones including total testosterone, LH, FSH, and GnRH were detected using radioimmunoassay. The sex ratio was examined by PCR and agarose gel electrophoresis. The results of D0, D21 and D28 showed significant increases compared with sham-exposed groups. The serum testosterone increased significantly in D0, D14, D21, and D28 compared with sham-exposed groups (p<0.05). Overall, this study suggested that EMP exposure may lead to the disturbance of reproductive hormone levels and affect the offspring sex ratio.

https://www.ncbi.nlm.nih.gov/pubmed/28735146

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Three Papers on Magnetoreception

Hore PJ, Mouritsen H. The Radical-Pair Mechanism of Magnetoreception.Annu Rev Biophys. 2016 Jul 5;45:299-344. doi: 10.1146/annurev-biophys-032116-094545.

Abstract

Although it has been known for almost half a century that migratory birds can detect the direction of the Earth's magnetic field, the primary sensory mechanism behind this remarkable feat is still unclear. The leading hypothesis centers on radical pairs-magnetically sensitive chemical intermediates formed by photoexcitation of cryptochrome proteins in the retina. Our primary aim here is to explain the chemical and physical aspects of the radical-pair mechanism to biologists and the biological and chemical aspects to physicists. In doing so, we review the current state of knowledge on magnetoreception mechanisms. We dare to hope that this tutorial will stimulate new interdisciplinary experimental and theoretical work that will shed much-needed additional light on this fascinating problem in sensory biology.

https://www.ncbi.nlm.nih.gov/pubmed/27216936


Bolte P et al. Localisation of the Putative Magnetoreceptive Protein Cryptochrome 1b in the Retinae of Migratory Birds and Homing Pigeons. PLoS One. 2016 Mar 8;11(3):e0147819. doi: 10.1371/journal.pone.0147819.

Abstract

Cryptochromes are ubiquitously expressed in various animal tissues including the retina. Some cryptochromes are involved in regulating circadian activity. Cryptochrome proteins have also been suggested to mediate the primary mechanism in light-dependent magnetic compass orientation in birds. Cryptochrome 1b (Cry1b) exhibits a unique carboxy terminus exclusively found in birds so far, which might be indicative for a specialised function. Cryptochrome 1a (Cry1a) is so far the only cryptochrome protein that has been localised to specific cell types within the retina of migratory birds. Here we show that Cry1b, an alternative splice variant of Cry1a, is also expressed in the retina of migratory birds, but it is primarily located in other cell types than Cry1a. This could suggest different functions for the two splice products. Using diagnostic bird-specific antibodies (that allow for a precise discrimination between both proteins), we show that Cry1b protein is found in the retinae of migratory European robins (Erithacus rubecula), migratory Northern Wheatears (Oenanthe oenanthe) and pigeons (Columba livia). In all three species, retinal Cry1b is localised in cell types which have been discussed as potentially well suited locations for magnetoreception: Cry1b is observed in the cytosol of ganglion cells, displaced ganglion cells, and in photoreceptor inner segments. The cytosolic rather than nucleic location of Cry1b in the retina reported here speaks against a circadian clock regulatory function of Cry1b and it allows for the possible involvement of Cry1b in a radical-pair-based magnetoreception mechanism.

https://www.ncbi.nlm.nih.gov/pubmed/26953791


Bazalova O et al. Cryptochrome 2 mediates directional magnetoreception in cockroaches.Proc Natl Acad Sci U S A. 2016 Feb 9;113(6):1660-5. doi: 10.1073/pnas.1518622113.

Abstract

The ability to perceive geomagnetic fields (GMFs) represents a fascinating biological phenomenon. Studies on transgenic flies have provided evidence that photosensitive Cryptochromes (Cry) are involved in the response to magnetic fields (MFs). However, none of the studies tackled the problem of whether the Cry-dependent magnetosensitivity is coupled to the sole MF presence or to the direction of MF vector. In this study, we used gene silencing and a directional MF to show that mammalian-like Cry2 is necessary for a genuine directional response to periodic rotations of the GMF vector in two insect species. Longer wavelengths of light required higher photon fluxes for a detectable behavioral response, and a sharp detection border was present in the cyan/green spectral region. Both observations are consistent with involvement of the FADox, FAD(•-) and FADH(-) redox forms of flavin. The response was lost upon covering the eyes, demonstrating that the signal is perceived in the eye region. Immunohistochemical staining detected Cry2 in the hemispherical layer of laminal glia cells underneath the retina. Together, these findings identified the eye-localized Cry2 as an indispensable component and a likely photoreceptor of the directional GMF response. Our study is thus a clear step forward in deciphering the in vivo effects of GMF and supports the interaction of underlying mechanism with the visual system.

https://www.ncbi.nlm.nih.gov/pubmed/26811445

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Joel M. Moskowitz, Ph.D., Director
Center for Family and Community Health
School of Public Health
University of California, Berkeley

Electromagnetic Radiation Safety
Website: http://www.saferemr.com
Facebook: http://www.facebook.com/SaferEMR
Twitter: @berkeleyprc

http://us15.campaign-archive2.com/?u=f11d48c2d17cb530fb48f00af&id=58ca5b4c03

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