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Bouisset N, Villard S, Legros A. Vestibular Extremely Low-Frequency Magnetic and Electric Stimulation Effects on Human Subjective Visual Vertical Perception. Bioelectromagnetics 2022; 43:355-367. [PMID: 35801487 PMCID: PMC9541167 DOI: 10.1002/bem.22417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 05/25/2022] [Accepted: 06/18/2022] [Indexed: 11/08/2022]
Abstract
Electric fields from both extremely low‐frequency magnetic fields (ELF‐MF) and alternating current (AC) stimulations impact human neurophysiology. As the retinal photoreceptors, vestibular hair cells are graded potential cells and are sensitive to electric fields. Electrophosphene and magnetophosphene literature suggests different impacts of AC and ELF‐MF on the vestibular hair cells. Furthermore, while AC modulates the vestibular system more globally, lateral ELF‐MF stimulations could be more utricular specific. Therefore, to further address the impact of ELF‐MF‐induced electric fields on the human vestibular system and the potential differences with AC stimulations, we investigated the effects of both stimulation modalities on the perception of verticality using a subjective visual vertical (SVV) paradigm. For similar levels of SVV precision, the ELF‐MF condition required more time to adjust SVV, and SVV variability was higher with ELF‐MF than with AC vestibular‐specific stimulations. Yet, the differences between AC and ELF‐MF stimulations were small. Overall, this study highlights small differences between AC and ELF‐MF vestibular stimulations, underlines a potential utricular contribution, and has implications for international exposure guidelines and standards. © 2022 Bioelectromagnetics Society.
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Affiliation(s)
- Nicolas Bouisset
- Human Threshold Research and Bioelectromagnetics Group, Imaging, Lawson Health Research Institute, London, Canada.,Department of Kinesiology, Western University, London, Canada
| | - Sébastien Villard
- Human Threshold Research and Bioelectromagnetics Group, Imaging, Lawson Health Research Institute, London, Canada.,Department of Kinesiology, Western University, London, Canada
| | - Alexandre Legros
- Human Threshold Research and Bioelectromagnetics Group, Imaging, Lawson Health Research Institute, London, Canada.,Department of Kinesiology, Western University, London, Canada.,Department of Medical Biophysics, Western University, London, Canada.,Department of Medical Imaging, Western University, London, Canada.,Euromov Digital Heath in Motion, Univ Montpellier, IMT Mines Ales, Montpellier, France.,EuroStim, Montpellier, France
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2
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Moretti J, Rodger J. A little goes a long way: Neurobiological effects of low intensity rTMS and implications for mechanisms of rTMS. CURRENT RESEARCH IN NEUROBIOLOGY 2022; 3:100033. [PMID: 36685761 PMCID: PMC9846462 DOI: 10.1016/j.crneur.2022.100033] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 01/26/2022] [Accepted: 02/15/2022] [Indexed: 01/25/2023] Open
Abstract
Repetitive transcranial magnetic stimulation (rTMS) is a widespread technique in neuroscience and medicine, however its mechanisms are not well known. In this review, we consider intensity as a key therapeutic parameter of rTMS, and review the studies that have examined the biological effects of rTMS using magnetic fields that are orders of magnitude lower that those currently used in the clinic. We discuss how extensive characterisation of "low intensity" rTMS has set the stage for translation of new rTMS parameters from a mechanistic evidence base, with potential for innovative and effective therapeutic applications. Low-intensity rTMS demonstrates neurobiological effects across healthy and disease models, which include depression, injury and regeneration, abnormal circuit organisation, tinnitus etc. Various short and long-term changes to metabolism, neurotransmitter release, functional connectivity, genetic changes, cell survival and behaviour have been investigated and we summarise these key changes and the possible mechanisms behind them. Mechanisms at genetic, molecular, cellular and system levels have been identified with evidence that low-intensity rTMS and potentially rTMS in general acts through several key pathways to induce changes in the brain with modulation of internal calcium signalling identified as a major mechanism. We discuss the role that preclinical models can play to inform current clinical research as well as uncover new pathways for investigation.
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Affiliation(s)
- Jessica Moretti
- School of Biological Sciences, The University of Western Australia, Perth, WA, Australia,Perron Institute for Neurological and Translational Science, Perth, WA, Australia
| | - Jennifer Rodger
- School of Biological Sciences, The University of Western Australia, Perth, WA, Australia,Perron Institute for Neurological and Translational Science, Perth, WA, Australia,Corresponding author. School of Biological Sciences M317, The University of Western Australia, 35 Stirling Highway, Crawley WA, 6009, Australia.
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3
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Omer H. Radiobiological effects and medical applications of non-ionizing radiation. Saudi J Biol Sci 2021; 28:5585-5592. [PMID: 34588869 PMCID: PMC8459055 DOI: 10.1016/j.sjbs.2021.05.071] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/26/2021] [Accepted: 05/27/2021] [Indexed: 11/21/2022] Open
Abstract
Radiation is used in medicine to diagnose and treat diseases but it can also cause harm to the body by burning or mutation. This depends on whether the radiation is ionizing or nonionizing. Despite its vast applications in surgery, dermatology and cosmetics, little is taught and thus known about non-ionizing radiation. This review article discusses the fundamentals of non-ionizing electromagnetic radiations. The main aim is to extensively explain the different types of non-ionizing radiation. This will equip students and medical personnel with knowledge on different medical applications and expose them to a variety of specializations in medicine that utilize non-ionizing radiation. The article discusses the physics, hazard, means of protection and medical application of each type of radiation: ultraviolet radiation, light (both visible light and LASER), infrared radiation, microwaves and extremely low frequency radiation separately. It presents these terms in a simple manner that avoids rigors mathematics and physics, which makes them comprehensible for medical students. The development of new diagnostic and therapeutic approaches could also lead to increased hazards to the body unless they are treated with precaution. If not adequately monitored, a significant health risk may be posed to potentially exposed employees. Hence proper dosage should be used for non-ionizing radiation. This is only possible through understanding of the risks/benefits of these radiations by studying the physics and radiobiological effects of each individual radiation.
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Affiliation(s)
- Hiba Omer
- Department of Basic Sciences Deanship of Preparatory Year and Supporting Studies, Imam Abdulrahman Bin Faisal University, P. O. Box 1982, Dammam 34212, Saudi Arabia
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A 50 Hz magnetic field affects hemodynamics, ECG and vascular endothelial function in healthy adults: A pilot randomized controlled trial. PLoS One 2021; 16:e0255242. [PMID: 34351946 PMCID: PMC8341886 DOI: 10.1371/journal.pone.0255242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 06/20/2021] [Indexed: 11/19/2022] Open
Abstract
Application of exposure to 50/60 Hz magnetic fields (MFs) has been conducted in the treatment of muscle pain and fatigue mainly in Japan. However, whether MFs could increase blood flow leading to muscle fatigue recovery has not been sufficiently tested. We investigated the acute effects of a 50 Hz sinusoidal MF at Bmax 180 mT on hemodynamics, electrocardiogram, and vascular endothelial function in healthy young men. Three types of regional exposures to a 50 Hz MF, i.e., forearm, upper arm, or neck exposure to MF were performed. Participants who received three types of real MF exposures had significantly increased ulnar arterial blood flow velocity compared to the sham exposures. Furthermore, after muscle loading exercise, MF exposure recovered hemoglobin oxygenation index values faster and higher than sham exposure from the loading condition. Moreover, participants who received real MF exposure in the neck region had significantly increased parasympathetic high-frequency activity relative to the sham exposure. The MF exposure in the upper arm region significantly increased the brachial artery flow-mediated dilation compared to the sham exposure. Computer simulations of induced in situ electric fields indicated that the order-of-magnitude estimates of the peak values were 100-500 mV/m, depending on the exposure conditions. This study provides the first evidence that a 50 Hz MF can activate parasympathetic activity and thereby lead to increase vasodilation and blood flow via a nitric oxide-dependent mechanism. Trial registration: UMIN Clinical Trial Registry (CTR) UMIN000038834. The authors confirm that all ongoing and related trials for this drug/intervention are registered.
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5
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Saito A, Wada K, Suzuki Y, Nakasono S. The response of the neuronal activity in the somatosensory cortex after high-intensity intermediate-frequency magnetic field exposure to the spinal cord in rats under anesthesia and waking states. Brain Res 2020; 1747:147063. [PMID: 32818531 DOI: 10.1016/j.brainres.2020.147063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 08/08/2020] [Accepted: 08/14/2020] [Indexed: 12/01/2022]
Abstract
Novel technologies using the intermediate-frequency magnetic field (IF-MF) in living environments are becoming popular with the advance in electricity utilization. However, the biological effects induced by the high-intensity and burst-type IF-MF exposure used in the wireless power transfer technologies for electric vehicles or medical devices, such as the magnetic stimulation techniques, are not well understood. Here, we developed an experimental platform using rats, that combined an 18 kHz, high-intensity (Max. 88 mT), Gaussian-shaped burst IF-MF exposure system with an in vivo extracellular recording system. In this paper, we aimed to report the qualitative differences in stimulus responses in the regions of the somatosensory cortex and peripheral nerve fibers that were induced by the IF-MF exposure to the rat spinal cord. We also report the modulation of the stimulus responses in the somatosensory cortex under anesthesia or waking states. Using this experimental platform, we succeeded in the detection of the motor evoked potentials or the neuronal activity in the somatosensory cortex that was induced by the IF-MF exposure to the spinal cord in rats. Compared to the state of anesthesia, the neuronal activities in the somatosensory cortex was enhanced during the waking state. On the other hand, these neuronal responses could not be confirmed by the IF-MF exposure-related coil sound only. Our experimental results indicated the basic knowledge of the biological responses and excitation mechanisms of the spinal cord stimulation by the IF-MF exposure.
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Affiliation(s)
- Atsushi Saito
- Biological Environment Sector, Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI), 1646 Abiko, Abiko-shi, Chiba, Japan.
| | - Keiji Wada
- Department of Electrical Engineering and Computer Science, Graduate School of Systems Design, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji-shi, Tokyo, Japan.
| | - Yukihisa Suzuki
- Department of Electrical Engineering and Computer Science, Graduate School of Systems Design, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji-shi, Tokyo, Japan.
| | - Satoshi Nakasono
- Biological Environment Sector, Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI), 1646 Abiko, Abiko-shi, Chiba, Japan.
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He Y, Sun W, Leung PSW, Chow YT. Effect of Static Magnetic Field of Electric Vehicles on Driving Performance and on Neuro-Psychological Cognitive Functions. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16183382. [PMID: 31547412 PMCID: PMC6765815 DOI: 10.3390/ijerph16183382] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 09/06/2019] [Accepted: 09/11/2019] [Indexed: 11/16/2022]
Abstract
Human neuropsychological reactions and brain activities when driving electric vehicles (EVs) are considered as an issue for traffic and public safety purposes; this paper examined the effect of the static magnetic field (SMF) derived from EVs. A lane change task was adopted to evaluate the driving performance; and the driving reaction time test and the reaction time test were adopted to evaluate the variation of the neuro-psychological cognitive functions. Both the sham and the real exposure conditions were performed with a 350 μT localized SMF in this study; 17 student subjects were enrolled in this single-blind experiment. Electroencephalographs (EEGs) of the subjects were adopted and recorded during the experiment as an indicator of the brain activity for the variations of the driving performance and of the cognitive functions. Results of this study have indicated that the impact of the given SMF on both the human driving performance and the cognitive functions are not considerable; and that there is a correlation between beta sub-band of the EEGs and the human reaction time in the analysis
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Affiliation(s)
- Yaqing He
- Department of Electrical Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, China.
| | - Weinong Sun
- Department of Electrical Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, China.
| | - Peter Sai-Wing Leung
- Department of Electrical Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, China.
- EMC Consortium Limited, Hong Kong, China.
| | - Yuk-Tak Chow
- Department of Electrical Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, China.
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Evans ID, Palmisano S, Loughran SP, Legros A, Croft RJ. Frequency‐dependent and montage‐based differences in phosphene perception thresholds via transcranial alternating current stimulation. Bioelectromagnetics 2019; 40:365-374. [DOI: 10.1002/bem.22209] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 07/06/2019] [Indexed: 11/11/2022]
Affiliation(s)
- Ian D. Evans
- School of PsychologyUniversity of Wollongong Wollongong Australia
- Illawarra Health and Medical Research InstituteUniversity of Wollongong Wollongong Australia
- Australian Centre for Electromagnetic Bioeffects Research Wollongong Australia
- Centre for Population Health Research on Electromagnetic EnergyMonash University Melbourne Australia
| | - Stephen Palmisano
- School of PsychologyUniversity of Wollongong Wollongong Australia
- Illawarra Health and Medical Research InstituteUniversity of Wollongong Wollongong Australia
| | - Sarah P. Loughran
- School of PsychologyUniversity of Wollongong Wollongong Australia
- Illawarra Health and Medical Research InstituteUniversity of Wollongong Wollongong Australia
- Australian Centre for Electromagnetic Bioeffects Research Wollongong Australia
- Centre for Population Health Research on Electromagnetic EnergyMonash University Melbourne Australia
| | - Alexandre Legros
- Lawson Health Research InstituteWestern University London Canada
| | - Rodney J. Croft
- School of PsychologyUniversity of Wollongong Wollongong Australia
- Illawarra Health and Medical Research InstituteUniversity of Wollongong Wollongong Australia
- Australian Centre for Electromagnetic Bioeffects Research Wollongong Australia
- Centre for Population Health Research on Electromagnetic EnergyMonash University Melbourne Australia
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8
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Saito A, Terai T, Makino K, Takahashi M, Yoshie S, Ikehata M, Jimbo Y, Wada K, Suzuki Y, Nakasono S. Real-time detection of stimulus response in cultured neurons by high-intensity intermediate-frequency magnetic field exposure. Integr Biol (Camb) 2018; 10:442-449. [PMID: 30052248 DOI: 10.1039/c8ib00097b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Threshold values of neuronal stimulation and modulation associated with exposure to time-varying electromagnetic fields contribute to establishing human protection guidelines and standards. However, biological evidence of threshold values in the intermediate-frequency range is limited. Additionally, although it is known that dendrites, a type of unmyelinated neuronal fibre, play an important role in information processing in the central nervous system, the stimulus threshold in dendrites has not been sufficiently investigated. We evaluated the excitation site-specific stimulus response of rat brain-derived cultured neurons by using a 20 kHz high-intensity intermediate-frequency magnetic field (hIF-MF) exposure system, a non-conductive fibre-optic imaging (NCFI) system, combined with a micro-patterning technique. Our hIF-MF exposure and NCFI system permitted real-time detection of the intracellular calcium ([Ca2+]i) spikes in neuronal cell bodies or unmyelinated neuronal fibres during exposure to a 20 kHz, 70 mT (peak), burst-type sinusoidal wave hIF-MF. Dosimetry of the induced electric fields intensities in the extracellular solution indicated that about 50% of unmyelinated neuronal fibres respond at about 147 V m-1. In contrast, the threshold of the [Ca2+]i spikes in neuronal cell bodies were lower than that in unmyelinated neuronal fibres. Our results provide a basis for understanding site-specific differences in the responses of cultured neurons to hIF-MFs.
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Affiliation(s)
- Atsushi Saito
- Biological Environment Sector, Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI), 1646 Abiko, Abiko, Chiba 270-1194, Japan.
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9
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Saito A, Takahashi M, Makino K, Suzuki Y, Jimbo Y, Nakasono S. Response of Cultured Neuronal Network Activity After High-Intensity Power Frequency Magnetic Field Exposure. Front Physiol 2018; 9:189. [PMID: 29662453 PMCID: PMC5890104 DOI: 10.3389/fphys.2018.00189] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 02/23/2018] [Indexed: 01/20/2023] Open
Abstract
High-intensity and low frequency (1-100 kHz) time-varying electromagnetic fields stimulate the human body through excitation of the nervous system. In power frequency range (50/60 Hz), a frequency-dependent threshold of the external electric field-induced neuronal modulation in cultured neuronal networks was used as one of the biological indicator in international guidelines; however, the threshold of the magnetic field-induced neuronal modulation has not been elucidated. In this study, we exposed rat brain-derived neuronal networks to a high-intensity power frequency magnetic field (hPF-MF), and evaluated the modulation of synchronized bursting activity using a multi-electrode array (MEA)-based extracellular recording technique. As a result of short-term hPF-MF exposure (50-400 mT root-mean-square (rms), 50 Hz, sinusoidal wave, 6 s), the synchronized bursting activity was increased in the 400 mT-exposed group. On the other hand, no change was observed in the 50-200 mT-exposed groups. In order to clarify the mechanisms of the 400 mT hPF-MF exposure-induced neuronal response, we evaluated it after blocking inhibitory synapses using bicuculline methiodide (BMI); subsequently, increase in bursting activity was observed with BMI application, and the response of 400 mT hPF-MF exposure disappeared. Therefore, it was suggested that the response of hPF-MF exposure was involved in the inhibitory input. Next, we screened the inhibitory pacemaker-like neuronal activity which showed autonomous 4-10 Hz firing with CNQX and D-AP5 application, and it was confirmed that the activity was reduced after 400 mT hPF-MF exposure. Comparison of these experimental results with estimated values of the induced electric field (E-field) in the culture medium revealed that the change in synchronized bursting activity occurred over 0.3 V/m, which was equivalent to the findings of a previous study that used the external electric fields. In addition, the results suggested that the potentiation of neuronal activity after 400 mT hPF-MF exposure was related to the depression of autonomous activity of pacemaker-like neurons. Our results indicated that the synchronized bursting activity was increased by hPF-MF exposure (E-field: >0.3 V/m), and the response was due to reduced inhibitory pacemaker-like neuronal activity.
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Affiliation(s)
- Atsushi Saito
- Biological Environment Sector, Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, Chiba, Japan
| | - Masayuki Takahashi
- Biological Environment Sector, Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, Chiba, Japan
| | - Kei Makino
- Department of Electrical and Electronic Engineering, Graduate School of Science and Engineering, Tokyo Metropolitan University, Tokyo, Japan
| | - Yukihisa Suzuki
- Department of Electrical and Electronic Engineering, Graduate School of Science and Engineering, Tokyo Metropolitan University, Tokyo, Japan
| | - Yasuhiko Jimbo
- Department of Precision Engineering, Graduate School of Engineering, University of Tokyo, Tokyo, Japan
| | - Satoshi Nakasono
- Biological Environment Sector, Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, Chiba, Japan
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10
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Effects of A 60 Hz Magnetic Field of Up to 50 milliTesla on Human Tremor and EEG: A Pilot Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2017; 14:ijerph14121446. [PMID: 29186760 PMCID: PMC5750865 DOI: 10.3390/ijerph14121446] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 11/15/2017] [Accepted: 11/20/2017] [Indexed: 11/16/2022]
Abstract
Humans are surrounded by sources of daily exposure to power-frequency (60 Hz in North America) magnetic fields (MFs). Such time-varying MFs induce electric fields and currents in living structures which possibly lead to biological effects. The present pilot study examined possible extremely low frequency (ELF) MF effects on human neuromotor control in general, and physiological postural tremor and electroencephalography (EEG) in particular. Since the EEG cortical mu-rhythm (8–12 Hz) from the primary motor cortex and physiological tremor are related, it was hypothesized that a 60 Hz MF exposure focused on this cortical region could acutely modulate human physiological tremor. Ten healthy volunteers (age: 23.8 ± 4 SD) were fitted with a MRI-compatible EEG cap while exposed to 11 MF conditions (60 Hz, 0 to 50 mTrms, 5 mTrms increments). Simultaneously, physiological tremor (recorded from the contralateral index finger) and EEG (from associated motor and somatosensory brain regions) were measured. Results showed no significant main effect of MF exposure conditions on any of the analyzed physiological tremor characteristics. In terms of EEG, no significant effects of the MF were observed for C1, C3, C5 and CP1 electrodes. However, a significant main effect was found for CP3 and CP5 electrodes, both suggesting a decreased mu-rhythm spectral power with increasing MF flux density. This is however not confirmed by Bonferroni corrected pairwise comparisons. Considering both EEG and tremor findings, no effect of the MF exposure on human motor control was observed. However, MF exposure had a subtle effect on the mu-rhythm amplitude in the brain region involved in tactile perception. Current findings are to be considered with caution due to the small size of this pilot work, but they provide preliminary insights to international agencies establishing guidelines regarding electromagnetic field exposure with new experimental data acquired in humans exposed to high mT-range MFs.
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11
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Deniz OG, Kaplan S, Selçuk MB, Terzi M, Altun G, Yurt KK, Aslan K, Davis D. Effects of short and long term electromagnetic fields exposure on the human hippocampus. J Microsc Ultrastruct 2017; 5:191-197. [PMID: 30023254 PMCID: PMC6025790 DOI: 10.1016/j.jmau.2017.07.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 06/05/2017] [Accepted: 07/02/2017] [Indexed: 12/23/2022] Open
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.
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Affiliation(s)
- Omur Gulsum Deniz
- Department of Histology and Embryology, Medical School of Ondokuz Mayıs University, Samsun, Turkey
| | - Suleyman Kaplan
- Department of Histology and Embryology, Medical School of Ondokuz Mayıs University, Samsun, Turkey
| | - Mustafa Bekir Selçuk
- Department of Radiology, Medical School of Ondokuz Mayıs University, Samsun, Turkey
| | - Murat Terzi
- Department of Neurology, Medical School of Ondokuz Mayıs University, Samsun, Turkey
| | - Gamze Altun
- Department of Histology and Embryology, Medical School of Ondokuz Mayıs University, Samsun, Turkey
| | - Kıymet Kübra Yurt
- Department of Histology and Embryology, Medical School of Ondokuz Mayıs University, Samsun, Turkey
| | - Kerim Aslan
- Department of Radiology, Medical School of Ondokuz Mayıs University, Samsun, Turkey
| | - Devra Davis
- Department of Medicine and Public Health, The Hebrew University, Jerusalem, Israel
- Environmental Health Trust, Teton Village, WY, USA
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12
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Modolo J, Thomas AW, Legros A. Human exposure to power frequency magnetic fields up to 7.6 mT: An integrated EEG/fMRI study. Bioelectromagnetics 2017. [PMID: 28628224 DOI: 10.1002/bem.22064] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We assessed the effects of power-line frequency (60 Hz in North America) magnetic fields (MF) in humans using simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). Twenty-five participants were enrolled in a pseudo-double-blind experiment involving "real" or "sham" exposure to sinusoidal 60 Hz MF exposures delivered using the gradient coil of an MRI scanner following two conditions: (i) 10 s exposures at 3 mT (10 repetitions); (ii) 2 s exposures at 7.6 mT (100 repetitions). Occipital EEG spectral power was computed in the alpha range (8-12 Hz, reportedly the most sensitive to MF exposure in the literature) with/without exposure. Brain functional activation was studied using fMRI blood oxygen level-dependent (BOLD, inversely correlated with EEG alpha power) maps. No significant effects were detected on occipital EEG alpha power during or post-exposure for any exposure condition. Consistent with EEG results, no effects were observed on fMRI BOLD maps in any brain region. Our results suggest that acute exposure (2-10 s) to 60 Hz MF from 3 to 7.6 mT (30,000 to 76,000 times higher than average public exposure levels for 60 Hz MF) does not induce detectable changes in EEG or BOLD signals. Combined with previous findings in which effects were observed on the BOLD signal after 1 h exposure to 3 mT, 60 Hz MF, this suggests that MF exposure in the low mT range (<10 mT) might require prolonged durations of exposure to induce detectable effects. Bioelectromagnetics. 38:425-435, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Julien Modolo
- Human Threshold Research and Bioelectromagnetics Group, Imaging Program, Lawson Health Research Institute, London, Canada.,Department of Medical Biophysics, Western University, London, Canada.,Department of Medical Imaging, Western University, London, Canada.,Institut National de la Santé et de la Recherche Médicale (INSERM), Rennes, France.,Laboratoire Traitement du Signal et de l'Image (LTSI), University of Rennes 1, LTSI, Rennes, France
| | - Alex W Thomas
- Human Threshold Research and Bioelectromagnetics Group, Imaging Program, Lawson Health Research Institute, London, Canada.,Department of Medical Biophysics, Western University, London, Canada.,Department of Medical Imaging, Western University, London, Canada
| | - Alexandre Legros
- Human Threshold Research and Bioelectromagnetics Group, Imaging Program, Lawson Health Research Institute, London, Canada.,Department of Medical Biophysics, Western University, London, Canada.,Department of Medical Imaging, Western University, London, Canada.,School of Kinesiology, Western University, London, Canada.,EuroMov, University of Montpellier, Montpellier, France
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13
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Takahashi M, Saito A, Jimbo Y, Nakasono S. Evaluation of the effects of power-frequency magnetic fields on the electrical activity of cardiomyocytes differentiated from human induced pluripotent stem cells. J Toxicol Sci 2017; 42:223-231. [PMID: 28321048 DOI: 10.2131/jts.42.223] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Although cardiac activity is known to differ between species in many respects, most evaluations of the cardiac effects of low-frequency electric and magnetic fields, which have a stimulant effect on electrically activated cells, have been performed in non-human experimental animals and cells, and the effects in humans have been assessed using theoretical models. In recent years, it has been verified that human cardiomyocytes differentiated from human induced pluripotent stem cells (hiPS-CM) are useful for evaluating human responses to various cardioactive compounds. In this study, we applied hiPSCMs for the first time to evaluate the human cardiac effects of power-frequency magnetic fields (MFs). After preparation of hiPS-CMs, we subjected a hiPS-CM monolayer formed on a multi-electrode array to short-term exposure to a 50 Hz MF at 400 mT with recording of the extracellular field potentials. The field potential duration of the hiPS-CMs did not differ significantly pre- and post-exposure, indicating that under these conditions, exposure to a 50 Hz MF at 400 mT does not affect the electrical activity of hiPSCMs.
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Affiliation(s)
- Masayuki Takahashi
- Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI)
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Saito A, Takahashi M, Jimbo Y, Nakasono S. Non-conductive and miniature fiber-optic imaging system for real-time detection of neuronal activity in time-varying electromagnetic fields. Biosens Bioelectron 2017; 87:786-793. [PMID: 27649336 DOI: 10.1016/j.bios.2016.09.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 08/29/2016] [Accepted: 09/06/2016] [Indexed: 10/21/2022]
Abstract
Establishing an appropriate threshold value for neuronal modulation by time-varying electromagnetic field (EMF) exposure is important for developing international guidelines to protect against the potential health effects, and to design a variety of medical devices. However, it is technically difficult to achieve real-time detection of neuronal activity under repetitive and long-term exposure to EMF. For this purpose, we developed a non-conductive, miniature, and flexible fiber-optic imaging system that does not affect the electromagnetic noise, induction heating, or vibration in a high-intensity and repetitive time-varying EMF exposure. Using the proposed system, we succeeded at real-time detection of spontaneous Ca2+ oscillations in single neuronal and glial cells, as well as synchronized bursting activities of multiple neuronal networks at a micrometer-scale and millisecond-order spatiotemporal resolution during long-term EMF exposure (sinusoidal wave, 20kHz, 8.6mT, >30min). The results indicated that short-term (<5min) exposure-related neuronal modulation was not detectable; however, long-term (15-30min) exposure was observed to depress neuronal activities. In addition, the simultaneous and real-time recording of neuronal activity and the environmental temperature revealed that the neuronal modulation was accompanied by a 0.5-1°C rise in the temperature of the culture medium induced by the heat generation of exposure coils. These findings suggest that our real-time imaging system can be used for precise evaluation of the threshold values and clarification of the mechanisms of neuronal modulation induced by time-varying EMF exposure.
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Affiliation(s)
- Atsushi Saito
- Biological Environment Sector, Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI), 1646 Abiko, Abiko-Shi, Chiba 270-1194, Japan.
| | - Masayuki Takahashi
- Biological Environment Sector, Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI), 1646 Abiko, Abiko-Shi, Chiba 270-1194, Japan
| | - Yasuhiko Jimbo
- Department of Precision Engineering, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo 113-8656, Japan
| | - Satoshi Nakasono
- Biological Environment Sector, Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI), 1646 Abiko, Abiko-Shi, Chiba 270-1194, Japan
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