Park JE, Seo YK, Yoon HH, Kim CW, Park JK, Jeon S · 2013
Researchers treated human bone marrow derived mesenchymal stem cells (hBM-MSCs) with ELF-EMF at 50 Hz and 1 mT and measured neural marker expression and cell signaling. The expression of neural markers NF-L, MAP2, and NeuroD1 increased at 6 days, while phosphorylation of Akt and CREB, but not ERK, increased at 90 min. The researchers suggest that EMF induces neural differentiation through activation of EGFR signaling and mild generation of reactive oxygen species (ROS).
Kurzeja E et al. · 2013
Researchers studied the potential relationship between static magnetic field exposure and the antioxidant system of fibroblasts cultured with fluoride ions. Three chambers with static magnetic fields of different intensities (0.4, 0.6, and 0.7 T) were used, and fluoride ions were added at a concentration of 0.12 mM. Static magnetic fields were found to reduce the oxidative stress caused by fluoride ions and to normalize the activities of antioxidant enzymes including superoxide dismutase, glutathione peroxidase, and catalase. The results also suggest that exposure to fluoride and a static magnetic field improves the tolerance of cells to the oxidative stress induced by fluoride ions.
Glinka M, Sieroń A, Birkner E, Cieślar G · 2013
Researchers measured the activity of antioxidant enzymes and a lipid peroxidation marker in male rats exposed to an extremely low-frequency magnetic field during skin wound healing. Each animal had an experimental cut wound on its back. The 40 Hz, 10 mT exposure was associated with increased glutathione peroxidase activity in serum and decreased malone dialdehyde in liver tissue, which the researchers described as suggesting inhibition of phospholipid peroxidation and stabilization of cellular membranes.
Calabrò E et al. · 2013
Researchers investigated the effects of exposing human SH-SY5Y neuronal-like cells to a uniform static magnetic field at an intensity of 2.2 mT. Fourier transform infrared spectroscopy analysis showed that exposure changed the secondary structure of cellular proteins and lipid components. A decrease of membrane mitochondrial potential up to 30% was measured after 24 h of exposure, and this effect was associated with reactive oxygen species production increase.
Xiong J, He C, Li C, Tan G, Li J, Yu Z, Hu Z, Chen F. · 2013
Researchers exposed rats to a 0.5 mT 50 Hz extremely low-frequency magnetic field for 14 and 28 days and then used Golgi staining to examine dendritic spines in the superficial layers of the medial entorhinal cortex. Exposure reduced spine density in stellate neurons and the basal dendrites of pyramidal neurons at both time points, largely due to loss of thin and branched spines. Reduced spine density in the apical dendrites of pyramidal neurons was only observed at 28 days, reflecting distinct vulnerability of spines in the apical and basal dendrites.
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.
Rauš S et al. · 2013
Researchers studied whether exposure to an extremely low-frequency magnetic field (ELF-MF, 50 Hz) affects postischemic damage in the hippocampus of Mongolian gerbils. After 10-min bilateral carotid occlusion, gerbils were continuously exposed to ELF-MF at an average magnetic induction of 0.5 mT for 7 days, with outcomes assessed on the seventh and 14th days after reperfusion. Ischemic gerbils exposed to ELF-MF had significantly lower cell loss and greater astrocyte and microglial responses compared with ischemic gerbils without exposure on the seventh day after reperfusion. By the 14th day after reperfusion, differences in the measured parameters were low and insignificant.
Manjhi J, Kumar S, Behari J, Mathur R. · 2013
Researchers studied whether extremely low frequency (ELF) magnetic field exposure could reduce osteoporosis caused by spinal cord injury in rats. Adult male Wistar rats (n = 24) were equally divided into sham, SCI, and SCI+MF groups. Starting one day after injury, the exposed group received ELF magnetic field at 17.96 micro-Tesla and 50 Hz for two hours per day over eight weeks. Bone mineral content, bone mineral density, and biochemical markers were significantly lower in spinal cord injury rats compared with the sham group, and these decreases were attenuated in the magnetic field-treated group, except for carbon content.
He YL, Liu DD, Fang YJ, Zhan XQ, Yao JJ, Mei YA. · 2013
Researchers investigated the effects of extremely low-frequency electromagnetic fields (ELF-EMF) on sodium channel activity in rat cerebellar granule cells. Exposing the cells to ELF-EMF for 10–60 minutes significantly increased sodium currents by 30–125% in a time- and intensity-dependent manner. Increases in intracellular arachidonic acid, prostaglandin E2, and phosphorylated PKA levels were observed in the cells following ELF-EMF exposure. The data demonstrated for the first time that neuronal sodium currents are significantly increased by ELF-EMF exposure via a cPLA2, arachidonic acid, prostaglandin E2, EP receptors, and PKA signaling pathway.
Gutiérrez-Mercado YK et al. · 2013
Researchers used 96 Wistar male rats divided into three groups of 32 rats each: a control group, a sham group, and an experimental group exposed to extremely low frequency magnetic fields at 120 Hz and 0.66 mT. All animals received colloidal carbon intravenously, and capillary permeability was studied using optical and transmission electron microscopy. In the exposed group, researchers detected an increase in capillary permeability and a significant increase in vascular area, effects not seen in the control or sham groups.
Esmekaya MA et al. · 2013
Researchers investigated the effects of a 50 Hz, 2 mT magnetic field, with or without iron(III) chloride, on the growth and morphology of Escherichia coli. No significant differences in cell viability were found between exposed and sham-exposed bacteria, and FeCl3 treatment also did not change cell viability. However, pore formations and membrane destruction were observed on the surface of cells exposed to the ELF field for 24 hours.
Calabrò E et al. · 2013
Researchers used SH-SY5Y neuroblastoma cells as an experimental model to study the effects of a 50 Hz electromagnetic field in the range from 50 µT to 1.4 mT. Fourier transform infrared spectroscopy analysis showed a reduction in intensity of the amide A band and a slight increase of vibration bands corresponding to methylene groups. Exposure to a 50 Hz electromagnetic field higher than 0.8 mT was associated with a significant reduction of cell viability and reduced mitochondrial transmembrane potential.
Balassa T et al. · 2013
Researchers exposed rats to extremely low-frequency magnetic fields (0.5 and 3 mT, 50 Hz) during two critical periods of brain development: in utero during the second gestation week, or as newborns for 7 days starting 3 days after birth. Basic excitability of hippocampal slices was increased by both the fetal 0.5 mT and the newborn 3 mT treatments. Fetal exposure significantly inhibited paired-pulse depression and significantly decreased the efficacy of long-term potentiation induction in the neocortex, but not in the hippocampus. Neonatal treatment had no significant effect on plasticity phenomena.
Bai WF, Xu WC, Feng Y, Huang H, Li XP, Deng CY, Zhang MS. · 2013
Researchers divided rat bone marrow stromal cells into three groups: one treated with electromagnetic fields, one induced without fields, and a control group. The cells in the EMF group expressed neuron-specific markers and genes, formed synaptic junctions, and pulsed excitatory postsynaptic currents. The researchers suggested that EMF appears to be a promising clinical option for stem cell transplantation therapies to combat central nervous system diseases.
Wang H et al. · 2013
Researchers exposed 100 Wistar rats to a 2.856 GHz pulsed microwave field at average power densities of 0, 5, 10, and 50 mW/cm² for 6 minutes. Rats exposed to 10 or 50 mW/cm² showed significant deficits in spatial learning and memory at 6 hours, 1 day, and 3 days after exposure. At the 5 mW/cm² level, exposed rats showed no difference compared with the sham group. The study suggested that impairment of LTP induction and damages of hippocampal structure, especially changes of synapses, might contribute to cognitive impairment after microwave exposure.
Tong J, Chen S, Liu XM, Hao DM · 2013
Researchers recorded hippocampal CA1 neuron activity in rats exposed to 900 MHz electromagnetic radiation at 10 W/m2 using glass electrode extracellular recording and a polygraph. Discharge frequency of hippocampal CA1 neurons was reduced after exposure, though the change in scale was not obvious. Electromagnetic radiation might change the spontaneous discharge patterns of hippocampus CA1 region neurons, making the explosive discharge pattern increase obviously. The researchers suggested that these changes may lead to a decrease in the ability of learning and memory.
Sharma A, Sisodia R, Bhatnagar D, Saxena VK · 2013
Researchers exposed Swiss albino mice to 10 GHz microwaves at a power density of 0.25 mW/cm2 for 2 hours per day for 30 days, then tested spatial memory using the Morris water maze test. Exposed mice showed statistically significant higher mean latency to reach the target quadrant compared to sham-exposed mice. A decrease in protein levels was also estimated in the whole brain of exposed mice compared to sham-exposed mice.
Moretti D et al. · 2013
Researchers developed a dedicated experimental setup for the simultaneous exposure of neuronal networks and monitoring of electrical activity. In this pilot study on 16 cultures, there was a 30% reversible decrease in firing rate and bursting rate during a 3-minute exposure. The researchers noted that additional experiments are needed to further characterize this effect.
Aboul Ezz HS, Khadrawy YA, Ahmed NA, Radwan NM, El Bakry MM · 2013
Researchers investigated the effect of electromagnetic radiation on concentrations of dopamine, norepinephrine, and serotonin in the hippocampus, hypothalamus, midbrain, and medulla oblongata of adult rats. Adult rats were exposed daily to electromagnetic radiation at 1800 MHz, with a specific absorption rate of 0.843 W/kg and power density of 0.02 mW/cm2, modulated at 217 Hz. Measurements were taken after 1, 2, and 4 months of daily exposure, and also after stopping exposure for 1 month following 4 months of daily exposure. The exposure resulted in significant changes in dopamine, norepinephrine, and serotonin in all four brain areas studied.
Unknown authors · 2012
Researchers used sixty-four four-month-old male Wistar rats divided into eight groups of eight rats each. Seven groups were exposed to varying dosages of manganese and a 50 Hz magnetic field of approximately 1 mT, while the last group served as a cage control. The study investigated interactions between the magnetic field and manganese and the elements calcium, zinc, magnesium, and phosphorus thought to be involved in caries in rat teeth. Levels of calcium, magnesium, zinc, and phosphorus in the experimental group rats were different from those in the control group.
Unknown authors · 2012
Researchers exposed Tuber borchii mycelium to a static magnetic field of 300 mT or an extremely low frequency magnetic field of 0.1 mT at 50 Hz for 1 h per day over three consecutive days. Gene expression and biochemical analyses were performed. ELF-MF exposure upregulated some genes involved in hyphal growth and increased the activity of many glycolytic enzymes. SMF exposure showed no differences in gene expression but increased the activities of glucose 6-phosphate dehydrogenase and hexokinase.
Unknown authors · 2012
Researchers measured unstimulated parotid salivary flow rate bilaterally in 142 individuals divided into heavy users and control subjects using a modified Schirmer test. Bilateral parotid ultrasonography was performed to evaluate gland volume. Heavy users showed a significant increase in salivary flow rate, blood flow rate, and parotid gland volume on the side where phones are frequently placed.
Ros-Llor I et al. · 2012
Researchers conducted a cohort study of 50 Caucasian mobile phone users, collecting two cheek mucosa cell samples from each participant. No statistically significant changes were recorded for age, gender, body mass index, or smoking status, and comparisons by phone side and exposure duration showed no significant differences. The authors reported no genotoxic effects from RF exposure for any study parameter.
Marjanović AM, Pavičić I, Trošić I · 2012
Radiation from man-made sources has exceeded natural radiation due to rapid technological progress. There is general concern about appliances using radiofrequency and microwave radiation, especially mobile communication systems. The authors identify reactive oxygen species generation as a plausible mechanism for radiofrequency and microwave radiation effects. Excessive reactive oxygen species production can overload antioxidant defenses and lead to cellular damage with potential for disease development. Further research is needed to understand the exact mechanism and consequences.
Laudisi F et al. · 2012
Researchers exposed pregnant mice to WiFi signals at 2450 MHz with a specific absorption rate of 4 W/kg for two hours daily during gestation. Thymocyte count, phenotype, and proliferation were unchanged in exposed offspring. These null effects were consistent in both sexes at 5 and 26 weeks of age.
