Erdal N, Gürgül S, Tamer L, Ayaz L · 2008
Researchers exposed adult Wistar-Albino rats to an extremely low frequency magnetic field (50 Hz, 1 mT, 4 hours per day) to study oxidative and nitrosative stress in liver tissue. 3-nitrotyrosine (3-NT) levels were significantly increased in exposed female rats compared to female controls, but no significant difference was found between exposed and control male rats. Malondialdehyde (MDA) levels showed no significant differences between control and exposed rats in either sex.
Canseven AG, Coskun S, Seyhan N · 2008
Researchers exposed guinea pigs to 50 Hz magnetic fields at 1, 2, and 3 mT for 4 h/day and 8 h/day for 5 days, measuring malondialdehyde, nitric oxide, glutathione, and myeloperoxidase activity in heart and liver tissues. MDA levels increased in the liver in some groups but decreased in both liver and heart in group VII. The researchers concluded that field intensity and exposure duration are among the conditions that influence free radical formation and antioxidant enzyme behavior.
Wang X et al. · 2008
Researchers exposed rats to extremely low-frequency electromagnetic fields (20 Hz, 14 mT) for one hour per day before daily morphine injections for 12 days, then measured dopamine D2 receptor density in the dorsal hippocampus during withdrawal. Morphine withdrawal alone significantly lowered D2 receptor density compared to saline controls, and ELF-EMF exposure during morphine treatment further reduced receptor density on the first and third withdrawal days. In both groups, D2 receptor density tended to recover as the number of withdrawal days increased.
Ross ML, Koren SA, Persinger MA. · 2008
Researchers tested whether a weak magnetic field pulsed over the left prefrontal brain region at the moment of accepting or refuting a statement could increase the likelihood of later accepting a false statement as true. Fifty men and women were each exposed to one of four magnetic field conditions, or a sham field, over the left prefrontal region above the eyebrow. Groups that received the burst-firing or 25 Hz pulsed fields during the refutation process accepted about twice the number of false statements as true compared to those in the 50 Hz or sham-field conditions. The treatments did not significantly affect the numbers of true statements accepted as false.
Piacentini R, Ripoli C, Mezzogori D, Azzena GB, Grassi C. · 2008
Partsvania B, Sulaberidze T, Modebadze Z, Shoshiashvili L. · 2008
Researchers studied how extremely low-frequency magnetic fields at 8.34 and 217 Hz affected the ability of single neurons in the mollusk Helix Pomatia to habituate to repeated stimuli. Brain ganglia were exposed to magnetic fields with peak values between 1 and 6 mT using Helmholtz coils, and neuron activity was recorded with a standard microelectrode technique. Exposure caused dehabituation, which the researchers described as occurring through degradation of the signal to noise ratio and alteration of the neuron's normal function.
Liu T, Wang S, He L, Ye K. · 2008
Researchers tested spatial learning and memory in rats using the Morris water maze after four weeks of daily exposure to a 50-Hz magnetic field of 2 mT for either one or four hours. Chronic exposure reduced the time rats took to find a hidden platform and improved long-term memory of the platform's former location. Short-term memory and motor activity were not affected.
Liu T, Wang S, He L, Ye K. · 2008
The study investigated whether anxiety levels could be affected by repeated extremely low frequency magnetic field (ELF MF) exposure of different daily durations. Rats exposed for 4 h/day showed increased anxiety-like behaviors in the open field test and the elevated plus maze test, without changes in locomotor activity, but showed no effect in the light/dark box test. Rats exposed for 1 h/day showed no effect in any of the tests.
Harakawa S et al. · 2008
Researchers examined how a 50 Hz sinusoidal electric field affected the voluntary behavior of Wistar rats using a conditioned place aversion response based on an aversive behavior against light environment. Rats conditioned without the electric field spent significantly less time in the white place, while rats conditioned with the electric field did not show such changes. The researchers considered that the aversion response to the light environment was interfered by exposure to the electric field.
Fu Y, Wang C, Wang J, Lei Y, Ma Y · 2008
Researchers exposed mice to 25 or 50 Hz electromagnetic fields for either 7 days or 25 days and then tested them in the Y-maze. Long-term exposure to 50 Hz fields reduced recognition of the novel arm. Neither short- nor long-term exposure to magnetic fields affected the locomotor activity of mice in the Y-maze.
Falone S et al. · 2008
Researchers continuously exposed female Sprague-Dawley rats to a sinusoidal 50 Hz, 0.1 mT magnetic field for 10 days. The study examined antioxidant protection systems and neurotrophic support in brain cortices, as a function of the age of the subjects. Exposure significantly affected antioxidant capability in both young and aged animals, but in opposite ways. The researchers suggested that exposure to these fields may act as a risk factor for oxidative stress-based nervous system pathologies associated with ageing.
Ahmed Z, Wieraszko A. · 2008
Researchers investigated the influence of a pulsed magnetic field on hippocampal evoked potentials in vitro. Exposure to a pulsed magnetic field at 0.16 Hz and 15 mT, applied for 30 minutes, amplified the population spike and the slope of EPSP recorded from hippocampal tissue. The amplification was additive to previously induced long-term potentiation and occurred in an NMDA-independent way. The pulsed magnetic field also modified paired-pulse facilitation and paired-pulse inhibition, suggesting it affects both excitatory and inhibitory processes in the hippocampus.
Yan JG, Agresti M, Zhang LL, Yan Y, Matloub HS. · 2008
Researchers exposed adult Sprague-Dawley rats to cell phones for 6 hours per day for 126 days and measured mRNA levels of several injury-associated proteins in the brain. The proteins evaluated included Calcium ATPase, Neural Cell Adhesion Molecule, Neural Growth Factor, and Vascular Endothelial Growth Factor. The results showed statistically significant mRNA up-regulation of these proteins in the brains of exposed rats.
Sokolovic D et al. · 2008
Researchers exposed Wistar rats to microwave radiation from a mobile test phone for 20, 40, and 60 days to evaluate oxidative stress in brain tissue and whether melatonin could reduce it. Exposure led to a significant increase in malondialdehyde and carbonyl group concentrations in brain tissue, along with decreased catalase activity and increased xanthine oxidase activity. Melatonin treatment significantly prevented the rise in MDA content and xanthine oxidase activity after 40 days of exposure, but was unable to prevent the decrease in catalase activity or the increase in carbonyl group content.
Odaci E, Bas O, Kaplan S · 2008
Researchers investigated the effects of prenatal EMF exposure on the number of granule cells in the dentate gyrus of 4-week-old rats. Pregnant rats in the exposed group were subjected to a 900 MHz EMF for 60 min/day between the first and last days of gestation. The results showed that prenatal EMF exposure caused a decrease in the number of granule cells in the dentate gyrus (P < 0.01).
Nittby H et al. · 2008
Researchers exposed rats to GSM-900 mobile phone radiation for 2 hours each week for 55 weeks at SAR levels of 0.6 and 60 mW/kg, then compared them to sham-exposed controls. GSM-exposed rats had impaired memory for objects and their temporal order of presentation compared to sham-exposed controls (P = 0.02). Detecting the place in which an object was presented was not affected by GSM exposure, and no difference in exploratory behaviour was seen in the open-field test.
Mathur R. · 2008
Researchers exposed growing rats to a radiofrequency field (73.5 MHz amplitude modulated, 16 Hz, SAR = 0.4 w/kg) for 45 days at 2 hours per day and recorded their responses to several types of noxious stimuli. The tonic pain rating was also decreased (p < 0.01), which the researchers said indicates analgesia in response to tonic pain. The data suggest that amplitude modulated RF field differentially affects the mechanisms involved in the processing of various noxious stimuli.
Lee KS, Choi JS, Hong SY, Son TH, Yu K. · 2008
Researchers studied biological effects of mobile phone 835 MHz electromagnetic fields in Drosophila at SAR 1.6 W/kg and SAR 4.0 W/kg. At SAR 1.6 W/kg, more than 90% of flies remained viable even after the 30 h exposure, while at SAR 4.0 W/kg viability dropped from the 12 h exposure. Both exposure levels triggered a stress response, increased reactive oxygen species production, and activated ERK and JNK signaling, but not p38 kinase signaling. SAR 4.0 W/kg strongly activated JNK signaling, expression of apoptotic genes, and amplified the number of apoptotic cells in the fly brain.
Joubert, V., Bourthoumieu, S., Leveque, P. and Yardin, C. · 2008
Researchers exposed rat primary neuronal cultures to a continuous-wave 900 MHz radiofrequency field at a specific absorption rate of 2 W/kg for 24 hours. A statistically significant difference in the rate of apoptosis was found in the RF-field-exposed neurons compared to the sham-, 37°C- and 39°C-exposed neurons either 0 or 24 h after exposure using both methods. The percentage of AIF-positive nuclei in RF-field-exposed neurons was increased by three- to sevenfold compared to other conditions, while no increase in caspase 3 activity was found.
Eberhardt JL, Persson BR, Brun AE, Salford LG, Malmgren LO · 2008
Researchers exposed rats to GSM microwave signals in the 900 MHz band and measured blood-brain barrier permeability and signs of neuronal damage after recovery periods of 14 or 28 days. Non-anaesthetized rats were sham exposed or exposed to microwaves for 2 hours at whole-body specific absorption rates of 0.12, 1.2, 12, or 120 mW/kg. Albumin leakage and its uptake into neurons was enhanced after 14 days but not after the 28-day recovery period, while the occurrence of dark neurons was enhanced after 28 days.
Croft RJ et al. · 2008
Researchers tested 120 healthy participants in a double-blind, counterbalanced crossover design, with each person receiving a 30-minute active and a 30-minute sham exposure one week apart while EEG data were recorded. The purpose of the study was to test one of the strongest findings in the literature, that of increased alpha power in response to MP-type radiation. Overall alpha power was enhanced during exposure, with the effect larger at sites on the same side as the exposure source than on the opposite side over posterior regions. After exposure ended, no overall change to alpha power was observed, though there was less alpha power contralateral to the exposure source relative to the ipsilateral side.
Ammari M, Lecomte A, Sakly M, Abdelmelek H, de-Seze R · 2008
Researchers measured cytochrome oxidase levels in rat brains using histochemical methods to evaluate regional brain metabolic activity after GSM 900 MHz signal exposure. Rats were exposed either for 45 minutes per day at a SAR of 1.5 W/Kg or for 15 minutes per day at a SAR of 6 W/Kg, over seven days. At 6 W/Kg, decreased CO activity was found in areas of the prefrontal and frontal cortex, the hippocampus, and the posterior cortex, while exposure at 1.5 W/Kg did not affect brain activity.
Ammari M et al. · 2008
Researchers measured GFAP expression in rat brain areas using immunocytochemistry to evaluate glial changes 10 days after chronic exposure to a GSM 900 MHz signal. Rats were exposed 5 days a week for 24 weeks at a brain-averaged SAR of 1.5 W/kg for 45 minutes per day, or at 6 W/kg for 15 minutes per day. Compared with sham or cage control animals, rats exposed at 6 W/kg had increased GFAP stained surface areas (p < 0.05), while exposure at 1.5 W/kg did not increase GFAP expression. The researchers noted that chronic exposure at 6 W/kg may induce persistent astroglia activation in the rat brain, which they described as a sign of a potential gliosis.
Zhang SZ, Yao GD, Lu DQ, Chiang H, Xu ZP. · 2008
Researchers exposed primary cultured rat neurons to 1.8 GHz RF EMF at a SAR of 2 W/kg and used a gene array to look for changes in gene expression. Among 1200 candidate genes screened, 24 were up-regulated and 10 were down-regulated, associated with functions including cytoskeleton, signal transduction, and metabolism. The effect of 24-hour exposure on gene expression was more obvious than that of 6-hour exposure, and intermittent exposure had a more obvious effect than continuous exposure.
Yao K, Wu W, Wang K, Ni S, Ye P, Yu Y, Ye J, Sun L. · 2008
Researchers exposed cultured human lens epithelial cells (HLECs) to a 1.8 GHz GSM radiofrequency field for 2 hours at specific absorption rates of 1, 2, 3, and 4 W/kg, then measured intracellular reactive oxygen species (ROS) and DNA damage. After exposure to 1.8 GHz RF for 2 h, HLECs exhibited significant intracellular ROS increase in the 2, 3, and 4 W/kg groups, and RF at 3 W/kg and 4 W/kg induced significant DNA damage consisting mainly of single strand breaks. When the radiofrequency field was superposed with 2 μT electromagnetic noise, the noise blocked the RF-induced ROS increase and DNA damage.
