Pooam M, Nakayama M, Nishigaki C, Miyata H · 2017
Researchers exposed RAW264 macrophage cells to a 50-Hz sinusoidal magnetic field at 0.1 mT or 0.5 mT and measured superoxide production, HSP70 expression, and mitochondrial membrane potential. The magnetic field enhanced production of superoxide and the expression of HSP70. The researchers suggested that the 50-Hz magnetic field diminished mitochondrial membrane potential, which led to increased superoxide production and HSP70 expression.
Martínez MA, Úbeda A, Moreno J, Trillo MÁ · 2016
Researchers investigated how power frequency magnetic fields affect cell proliferation in NB69 cells and the role of p38 and JNK kinases and reactive oxygen species in that response. NB69 cultures were exposed to a 100 µT magnetic field, either intermittently for 24, 42 or 63 hours, or continuously for periods of 15 to 120 minutes, with or without p38 or JNK inhibitors and an antioxidant. Field exposure induced transient activation of p38, JNK, and ERK1/2, but only the p38 inhibitor blocked the proliferative effect. The antioxidant NAC blocked the field effects on cell proliferation and p38 activation, but not those on ERK1/2 activation.
Djordjevic B et al. · 2015
Serbian researchers exposed rats to 900 MHz microwave radiation (similar to cell phone frequencies) for 4 hours daily over 20-60 days and found significant liver damage, including increased oxidative stress and cellular damage markers. When rats were also given melatonin supplements, the treatment partially protected against some of the radiation-induced liver damage. This suggests that microwave radiation can harm liver function, but natural antioxidants like melatonin may offer some protection.
Lai J et al. · 2015
Sixty adult male rats were randomly assigned to a sham group or a 50 Hz/100 µT ELF-EMF exposure group for 24 weeks. During the exposure period, body weight, food intake, and water intake were recorded and showed no differences between groups. Behavioral tests for anxiety, depression, cognition, and memory found no effects of ELF-EMF, and brain morphology and histology were unchanged.
Djordjevic B et al. · 2015
Researchers studied whether melatonin treatment (2 mg/kg) might favorably impact liver tissue in rats exposed to microwave radiation. The experiment used 84 six-weeks-old Wistar male rats exposed for 4 hours a day to microwaves at 900 MHz for 20, 40, and 60 days. Microwave exposure increased malondialdehyde after 40 days, protein carbonyl content after 20 days, and catalase and xanthine oxidase activity after 40 days. Melatonin reduced malondialdehyde after 40 days but had no effect on the other analyzed parameters.
Masoudian N et al. · 2015
Researchers exposed synaptosomes, used as a model of nervous terminals, to extremely low frequency electromagnetic fields (ELF-EMF) at flux intensities from 0.1 to 2 mT and frequencies from 50 to 230 Hz. An artificial neural network program was used to analyze the raw data and predict effects across the tested range. Glutamate concentration changes fell between -35 and +40% compared to normal state, which the researchers interpreted as the glutamatergic system attempting to compensate for environmental changes.
Zhang Y, Liu X, Zhang J, Li N. · 2015
Researchers exposed rats to extremely low frequency electromagnetic fields (the type emitted by power lines and electrical devices) for 12 weeks to see if it would affect memory and brain health, particularly markers associated with Alzheimer's disease. They found no changes in the rats' memory performance, brain tissue structure, or levels of amyloid-beta proteins that are linked to Alzheimer's. This suggests that short-term exposure to these fields at the levels tested did not harm cognitive function in this animal model.
Kesari KK, Luukkonen J, Juutilainen J, Naarala J · 2015
Human SH-SY5Y neuroblastoma cells were exposed to a 50 Hz, 100 μT magnetic field for 24 hours with or without menadione co-exposure. Micronuclei, reactive oxygen species, and lipid peroxidation were measured at 15, 30, and 45 days after exposure. Micronuclei levels were significantly elevated at 15 and 30 days but not at 45 days after exposure. Lipid peroxidation was significantly decreased at 30 and 45 days after exposure.
Afrasiabi A et al. · 2014
Researchers prepared synaptosome suspensions from the cerebral cortex of sheep brain and exposed them to extremely low frequency electromagnetic fields (ELF-EMFs). The exposures tested frequencies from 50 Hz to 230 Hz, flux intensities from 0.1 mT to 1.7 mT, and durations between 15 and 120 min. Acetylcholinesterase (AChE) activity was measured by the Ellman method, and the data were analyzed using neural network based software, Inform 4.02, to predict activity patterns through nine 3D curves. AChE activity was found to decrease at field intensities of 1.2 mT to 1.7 mT and frequencies of 50 Hz to 90 Hz.
Komaki A, Khalili A, Salehi I, Shahidi S, Sarihi A. · 2014
Researchers exposed rats to 50Hz electromagnetic fields from power lines for 90 days and found enhanced brain connections in the hippocampus, the memory center. This suggests chronic exposure to everyday electrical fields may alter how our brains process and store information.
Komaki A, Khalili A, Salehi I, Shahidi S, Sarihi A. · 2014
Researchers divided twenty-nine adult male Wistar rats into three groups: an ELF-EMF exposed group, a sham group, and a control group. The exposed rats received a 50 Hz, 100 micro Tesla magnetic field for 90 consecutive days at 2 hours per day. Prolonged exposure to ELF-EMFs increased LTP induction, and there was a significant difference in the slope of EPSP and amplitude of PS between the ELF-EMF group and other groups. The researchers' data suggest that exposure to ELF-EMFs produces a marked change in the synaptic plasticity generated in synapses of the PP-DG.
Mahdavi SM, Sahraei H, Yaghmaei P, Tavakoli H. · 2014
Researchers studied the effects of extremely low frequency electromagnetic field (ELF-EMF) exposure at 1 and 5 Hz on behavioral, hormonal, and metabolic changes in male Wistar rats. Plasma ACTH concentration increased in both frequency groups, while noradrenaline concentration showed an overall reduction.
Zhang Y, Liu X, Zhang J, Li N. · 2014
Researchers exposed 20 healthy male Sprague Dawley rats to 100 μT/50 Hz ELF-EMF or sham exposure for 12 weeks. The Morris water maze test showed no cognitive or memory impairment in the exposed rats compared to sham-exposed rats. Body weight, Aβ levels, and neuron morphology showed no significant changes between groups.
Li Y, Zhang C, Song T. · 2014
Researchers exposed Sprague-Dawley rats to Morris water maze training, ELF-MF exposure (50 Hz, 100 microT), or combined training and exposure for 90 days, with normal rats as controls. Previous training improved spatial acquisition in the Morris water maze and this effect lasted at least 90 days. However, this improvement was not observed during the probe trial. ELF-MF exposure did not significantly differ from controls and did not interfere with training-related improvements.
Li Y, Yan X, Liu J, Li L, Hu X, Sun H, Tian J. · 2014
Researchers examined the effects of pulsed electromagnetic field (PEMF) exposure on brain-derived neurotrophic factor (BDNF) gene expression in cultured dorsal root ganglion neurons from neonatal rats. Exposure to 50 Hz and 1 mT PEMF for 2 hours increased both intracellular free calcium levels and Bdnf mRNA expression. The increase in calcium was found to come from influx through L-type voltage-gated calcium channels, while calcium mobilization from internal stores was not involved. Blocking the Erk signaling pathway strongly inhibited PEMF-related Erk1/2 activation and BDNF expression, indicating that Erk activation was required for PEMF-induced BDNF upregulation.
Shafiei SA, Firoozabadi SM, Tabatabaie KR, Ghabaee M. · 2014
Researchers investigated how extremely low-frequency magnetic fields (ELF-MFs) applied to different parts of the brain changed EEG power spectrum readings. EEG relative power spectrum was evaluated at several brain points when exposed to magnetic fields at 45, 17, 10, 5, and 3 Hz frequencies, at intensities of 0, 100, 240, or 360 μT across four sessions. Significant changes were observed in different EEG bands, and some exposures decreased the alpha band in frontal and central areas in the closed-eyes state.
Luukkonen J, Liimatainen A, Juutilainen J, Naarala J · 2014
Researchers exposed human SH-SY5Y neuroblastoma cells to a 50-Hz, 100-μT magnetic field for 24 hours, followed by a 3-hour exposure to menadione. The study aimed to investigate cellular changes occurring during the first 24 hours of magnetic field exposure and whether those changes could lead to genomic instability in the progeny of exposed cells. Magnetic field exposure was associated with increased micronuclei at 8 and 15 days after exposure, increased mitochondrial activity at 8 days, and increased reactive oxygen species production and lipid peroxidation at 15 days. The researchers suggest that magnetic field exposure disturbs oxidative balance immediately after exposure, and that persistently elevated levels of micronuclei were found in the progeny of exposed cells.
Zhang C, Li Y, Wang C, Lv R, Song T. · 2013
Researchers exposed rats to 50 Hz magnetic fields (the type from power lines) for 12 weeks to see if this exposure would worsen Alzheimer's-like symptoms caused by aluminum poisoning. They found that magnetic field exposure alone had no effect on brain function or Alzheimer's markers, and it didn't make aluminum-induced brain damage any worse. This suggests that power-frequency magnetic fields may not contribute to Alzheimer's disease development.
Akdag MZ, Dasdag S, Cakir DU, Yokus B, Kizil G, Kizil M. · 2013
Researchers exposed rats to magnetic fields at levels considered safe by current standards for 10 months. The exposure significantly increased two markers of brain cell damage and aging, suggesting that even "safe" magnetic field levels may cause harmful oxidative stress in brain tissue over time.
Akdag MZ, Dasdag S, Cakir DU, Yokus B, Kizil G, Kizil M. · 2013
Researchers exposed adult male Sprague-Dawley rats to 50 Hz ELF magnetic fields at 100 or 500 μT for 2 hours per day for 10 months, then measured beta-amyloid protein, protein carbonyl, and malondialdehyde in the brain. Protein carbonyl and malondialdehyde levels were increased by exposure to both field strengths, while beta-amyloid protein levels were not significantly changed.
Akdag MZ et al. · 2013
No significant differences were found in reproductive or oxidative stress parameters between sham and exposed groups. The 500 μT exposure increased the final apoptosis score compared with sham, whereas the 100 μT exposure did not.
Zhang C, Li Y, Wang C, Lv R, Song T · 2013
Researchers exposed Sprague-Dawley rats to ELF-MF at 100 µT and 50 Hz with or without oral aluminum for 12 weeks. Oral aluminum treatment caused learning and memory impairment, neuronal cell loss, and high amyloid-β density in the hippocampus and cerebral cortex. ELF-MF alone showed no significant effect on Alzheimer's disease pathogenesis. Combined ELF-MF and aluminum exposure did not cause more damage than aluminum alone.
Selaković V, Rauš Balind S, Radenović L, Prolić Z, Janać B. · 2013
Scientists exposed gerbils to power line frequency magnetic fields for seven days. The exposure increased brain cell damage in all tested regions, with stronger effects in older animals and at higher field strengths. Younger brains recovered better after exposure ended, suggesting age affects vulnerability.
Selaković V, Rauš Balind S, Radenović L, Prolić Z, Janać B. · 2013
Researchers investigated the effects of extremely low frequency magnetic fields (ELF-MF; 50 Hz; 0.1, 0.25 and 0.5 mT) on oxidative stress in the brains of 3-month-old (adult) and 10-month-old (middle-aged) Mongolian gerbils. Nitric oxide level, superoxide production, superoxide dismutase activity, and index of lipid peroxidation were measured in the forebrain cortex, striatum, hippocampus, and cerebellum immediately and 3 days after cessation of 7-day exposure. ELF-MF significantly increased oxidative stress in all tested brain regions, and the effect was higher in middle-aged gerbils and correlated with the value of magnetic induction.
Janać B et al. · 2012
Researchers investigated how extremely low frequency magnetic fields affected locomotion, stereotypy, and immobility in 3- and 10-month-old male Mongolian gerbils. The animals were continuously exposed to ELF-MF for seven days. In the younger gerbils, all three field strengths increased locomotion and stereotypy and decreased immobility. In the older gerbils, the lowest field strength decreased motor behavior, the middle strength produced a slight increase, and the highest strength produced a pronounced stimulation.
