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.
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.
Pelletier A et al. · 2013
Researchers examined the effects of chronic RF-EMF exposure (900 MHz, 1 V m(-1)) on the main functions involved in body energy homeostasis, including feeding behaviour, sleep, and thermoregulatory processes. Thirteen juvenile male Wistar rats were exposed to continuous RF-EMF for 5 weeks and compared with 11 non-exposed animals. The frequency of rapid eye movement sleep episodes was greater in the exposed group independently of ambient temperature, with increases of 42.1% at 24 °C and 31.6% at 31 °C. Exposure also increased daytime food intake, and the researchers concluded that RF-EMF exposure can induce energy-saving processes without strongly disturbing the overall sleep pattern.
Odacı E et al. · 2013
Researchers exposed pregnant rats to 900 MHz electromagnetic fields for one hour daily between days 13 and 21 of pregnancy, then assessed the female pups' spinal cord tissue and motor behavior. The rotarod test showed a significant increase in motor functions in the EMF group pups (p=0.037), while the open field test found no difference between groups. Pathological changes were observed in the spinal cords of the EMF group pups, and the researchers suggested these changes may have led to the increase in motor activity.
Ntzouni MP et al. · 2013
Narayanan SN et al. · 2013
Researchers exposed male adolescent rats to radio-frequency electromagnetic radiation at 900 MHz from an active mobile phone, then tested their emotionality and locomotion. In the elevated plus maze test, exposed rats showed significantly reduced open-arm entries, time on open arms, and distance on open arms, along with decreased rearing and grooming frequency. Total distance travelled and total arm entries did not differ significantly between exposed and control rats.
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.
Mandalà M et al. · 2013
Researchers conducted a study to verify whether Bluetooth devices reduce the auditory nerve effects seen with direct mobile phone electromagnetic field exposure, using the same experimental protocol as a prior investigation. Twelve patients underwent retrosigmoid vestibular neurectomy to treat definite unilateral Ménière's disease while being monitored with acoustically evoked CNAPs during direct mobile phone or Bluetooth headset exposure. Bluetooth electromagnetic fields did not produce any significant change in cochlear nerve activity, while mobile phone electromagnetic fields caused a significant decrease in CNAP amplitude and an increase in latency in all subjects.
Lv B, Chen Z, Wu T, Shao Q, Yan D, Ma L, Lu K, Xie Y. · 2013
Eighteen subjects participated in a double-blind, crossover, randomized and counterbalanced experiment including real and sham exposure sessions. Resting-state fMRI signals were collected before and after exposure, with the radiation source placed close to the right ear. After real exposure, decreased ALFF values were found in the left superior temporal gyrus, left middle temporal gyrus, right superior temporal gyrus, right medial frontal gyrus, and right paracentral lobule.
