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.
Wang X et al. · 2013
Researchers exposed early adolescent male mice to a 50 Hz magnetic field at 2 mT for 60 minutes per day from postnatal day 23 to 35. Spatial memory was then tested using the Y-maze and Morris water maze tasks. The magnetic field exposure did not affect Y-maze performance but improved spatial learning acquisition and memory retention in the water maze.
Todorović D et al. · 2013
Researchers analyzed pupa-adult development and motor behaviour of Tenebrio obscursus and T. molitor after exposure to a static magnetic field of 50 mT. The static magnetic field did not affect the pupa-to-adult developmental timing in either species. Motor behaviour of T. obscurus adults was not significantly changed by the magnetic field, but changes were seen in T. molitor.
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.
Kumar S et al. · 2013
Researchers studied the effect of a 50 Hz, 17.96 μT magnetic field on tonic pain behavior and brain neurotransmitters in rats with complete thoracic spinal cord injury at week 8. Adult male Wistar rats were divided into Sham, SCI, and SCI+MF groups, with pain behavior assessed using block pain rating, session pain rating, time spent in pain categories, and flinch counts. Pain ratings and flinch counts were significantly lower in SCI rats than in Sham rats, but these measures were comparable between the SCI+MF and Sham groups. Serotonin was lower in the cortex, remaining forebrain areas, and brainstem, while GABA and norepinephrine were higher in the brainstem of SCI rats, but these levels were comparable to Sham in the SCI+MF group.
Kitaoka K, Kitamura M, Aoi S, Shimizu N, Yoshizaki K. · 2013
Researchers investigated whether chronic extremely low-frequency magnetic field exposure affected emotional behavior and corticosterone synthesis in mice, using an intensity of 3 mT over a total exposure of 200 hours. Exposed mice showed a significant increase in total immobility time in a forced swim test and showed latency to enter the light box in a light-dark transition test, compared with sham-treated mice. Corticosterone secretion was significantly high in the exposed mice, but no changes were observed in adrenocorticotropic hormone or stress-response gene expression, and Cyp17a1 mRNA was significantly reduced.
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.
El Gohary MI, Salama AA, El Saeid AA, El Sayed TM, Kotb HS. · 2013
Researchers studied how caffeine and extremely low-frequency magnetic field (ELF-MF) exposure affected brain electrical activity in rats over 15 days. Caffeine given at 10 mg/kg caused a reduction in the mean power amplitude of EEG signals across most frequency bands, especially the alpha band (8–12 Hz), and this effect was more evident in motor cortex than in visual cortex. Exposure to ELF-MF at 0.2 mT enhanced mean power amplitude in most EEG frequency bands, with the effect more pronounced in the right hemisphere than the left. When caffeine was given alongside ELF-MF exposure, a large increase in alpha-band amplitude appeared after 5 days at all recording sites.
Duan Y, Wang Z, Zhang H, He Y, Lu R, Zhang R, Sun G, Sun X. · 2013
Researchers investigated whether lotus seedpod procyanidins (LSPCs) given by oral gavage could protect mice from cognitive deficits and oxidative damage caused by extremely low frequency electromagnetic field (ELF-EMF) exposure at 50 Hz and 8 mT for 28 days. A water maze test indicated that learning and memory abilities of the ELF-EMF group deteriorated significantly compared with the control group, but the ELF-EMF + LSPCs90 group had remarkably improved learning and memory abilities compared with the ELF-EMF group. ELF-EMF exposure was associated with significant increases in oxidative stress markers and decreases in antioxidant enzyme activities.
Deng Y, Zhang Y, Jia S, Liu J, Liu Y, Xu W, Liu L. · 2013
Researchers divided sixty male SPF Kunming mice into four groups: a control group, an ELF-MF group exposed at 2 mT for 4 hours per day, a group given aluminum at 200 mg per kg, and a combined ELF-MF plus aluminum group. After 8 weeks of treatment, all three exposure groups showed learning memory impairment, with prolonged escaping latency to the platform and a reduced percentage of time in the platform quadrant in the Morris water maze task. All three exposed groups showed a statistically significant decrease in superoxide dismutase activity and an increase in malondialdehyde levels. The combined ELF-MF plus aluminum treatment induced no more damage than ELF-MF and aluminum did separately.
Celik MS et al. · 2013
Researchers studied whether extremely low-frequency magnetic field (ELF-MF) exposure affects how manganese accumulates in rat organs. A total of 40 rats were randomly divided into eight groups, with four groups also exposed to ELF-MF at 1.5 mT and 50 Hz for 4 hours, 5 days a week, over 45 days. Manganese levels in the brain, kidney, and liver were higher in groups that received both manganese and ELF-MF exposure than in groups that received manganese alone.
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.
Amirifalah Z, Firoozabadi SM, Shafiei SA. · 2013
Researchers exposed 10 healthy women to a pulsed extremely low-frequency magnetic field at the central brain areas corresponding to electrodes C3 and C4, then measured changes in EEG activity. After exposure, beta (15-25 Hz), sensorimotor rhythm (13-15 Hz), and theta (4-8 Hz) powers were significantly decreased by 12.0% to 26.6% at 10 Hz in the C3 and C4 regions, compared with values measured during exposure. The study suggests that this technique may be applied in the treatment of anxiety, though further investigation is needed.
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.
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.
Vecsei Z, Csathó A, Thuróczy G, Hernádi I · 2013
Researchers tested the effects of UMTS RF EMF exposure on the thermal pain threshold of 20 young adult volunteers, measuring responses on the surface of the fingers. The exposure lasted 30 minutes and was applied to the head through a patch antenna, with SAR kept constant at 1.75 W/kg. Thermal pain thresholds were intact, but a reduced desensitization effect between repeated stimulations was observed on the contralateral side during genuine UMTS exposure. Subjective pain ratings were marginally decreased in the genuine exposure condition only.
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.
