Brain & Nervous System

Ten gigahertz microwave radiation impairs spatial memory, enzymes activity, and histopathology of developing mice brain

Sharma A, Kesari KK, Saxena VK, Sisodia R. · 2017

Effects of prenatal exposure to WIFI signal (2.45GHz) on postnatal development and behavior in rat: Influence of maternal restraint.

Othman H, Ammari M, Sakly M, Abdelmelek H. · 2017

Researchers randomly assigned 24 pregnant albino Wistar rats to four groups: control, WiFi-exposed, restrained, and both WiFi-exposed and restrained. Each WiFi exposure and restraint session lasted 2 hours per day throughout gestation until parturition. Prenatal WiFi exposure and restraint, separately and especially combined, adversely affected offspring physical development, neuromotor maturation, adult emotional responses, motor and exploratory behavior, brain oxidative stress, and serum biochemistry, with most impacts depending on offspring gender.

The effect of Wi-Fi electromagnetic waves in unimodal and multimodal object recognition tasks in male rats

Hassanshahi A et al. · 2017

Researchers exposed 80 male Wistar rats to 2.4 GHz Wi-Fi radiation for 30 days at 12 hours per day. Exposed rats could not discriminate between novel and familiar objects in standard, tactile, visual, and cross-modal object recognition tests. M1 receptor expression increased after Wi-Fi exposure. The researchers concluded that chronic Wi-Fi exposure might impair both unimodal and cross-modal information encoding.

Effects of acute and chronic exposure to both 900 MHz and 2100 MHz electromagnetic radiation on glutamate receptor signaling pathway.

Gökçek-Saraç Ç et al. · 2017

Rats were exposed to 900 and 2100 MHz RF-EMR for 2 h/day for either 1 week (acute) or 10 weeks (chronic). The study measured hippocampal levels and activity of PKA, CaMKIIα, CREB, and p44/42 MAPK from NMDAR-related signaling pathways using Western blotting and activity assays. Chronic exposure produced significantly higher enzyme levels than acute exposure at both frequencies, and 2100 MHz exposure produced higher levels than 900 MHz in both acute and chronic groups.

Effects of short and long term electromagnetic fields exposure on the human hippocampus

Deniz OG et al. · 2017

Researchers studied 60 healthy female medical students divided into low (<30 min daily) and high (>90 min daily) mobile phone exposure groups. Hippocampal volume and metabolite levels did not differ significantly between groups. However, the high exposure group performed significantly worse on Stroop and digit span backward tests of attention.

Personal radiofrequency electromagnetic field exposure measurements in Swiss adolescents.

Roser K et al. · 2017

Researchers measured personal RF-EMF exposure in 90 adolescents aged 13 to 17 years using a portable ExpoM-RF device across 13 frequency bands from 470 to 3600 MHz for three consecutive days with a time-activity diary. Mobile phones contributed 67.2% and mobile phone base stations contributed 19.8% of total personal RF-EMF measurements averaging 63.2 μW/m² (0.15 V/m). WLAN at school and home accounted for 3.5% of total personal measurements. Environmental sources contributed on average 6.0% to the brain dose and 9.0% to the whole-body dose according to dose calculations.

Effects of GSM and UMTS mobile telephony signals on neuron degeneration and blood-brain barrier permeation in the rat brain.

Poulletier de Gannes F et al. · 2017

Oxidative stress response in SH-SY5Y cells exposed to short-term 1800 MHz radiofrequency radiation

Marjanovic Cermak AM, Pavicic I, Trosic I · 2017

Human neuroblastoma SH-SY5Y cells were exposed to 1800 MHz radiofrequency radiation for 10, 30, and 60 minutes at an electric field strength of 30 V m-1 and a specific absorption rate of 1.6 W kg-1. Cell viability remained within normal physiological values after radiation exposure. Significantly higher ROS levels were observed at every radiation exposure time tested. After 60 minutes of exposure, the radiation caused significant lipid and protein damage. The highest glutathione concentration was detected after 10 minutes of exposure.

Acute Neuroinflammation Promotes Cell Responses to 1800 MHz GSM Electromagnetic Fields in the Rat Cerebral Cortex.

Lameth J et al. · 2017

Researchers investigated whether a 2-hour head-only exposure to GSM-1800 MHz could affect a neuroinflammatory reaction triggered by lipopolysaccharide in 2-week-old or adult rats. In developing rats, 24 hours after exposure, cortical interleukin-1β and NOX2 NADPH oxidase transcripts were reduced by 50 to 60% compared with sham-exposed animals. Adult rats showed a 50% reduction in IL1β mRNA but no NOX2 suppression and displayed a significant growth response of microglial cell processes. GSM exposure decreased phosphorylation at two residues on the GluA1 AMPA receptor subunit (serine 831 and 845). The changes in gene expression, microglia, and GluA1 phosphorylation did not persist 72 hours after exposure and were absent without LPS pretreatment.

Behavioral testing of mice exposed to intermediate frequency magnetic fields indicates mild memory impairment.

Kumari K et al. · 2017

Researchers exposed mice to 7.5 kHz magnetic fields at 12 or 120 μT for 5 weeks. No effects were seen on body weight, spontaneous activity, motor coordination, anxiety, or aggression. In the Morris swim task, the 120 μT group showed a less steep learning curve than other groups. The passive avoidance task revealed a clear memory impairment over 48 hours in the 120 μT group. Hippocampal astroglial activation and neurogenesis were unchanged, while tumor necrosis factor alpha mRNA increased significantly in the 120 μT group.

Exposure to 835 MHz radiofrequency electromagnetic field induces autophagy in hippocampus but not in brain stem of mice.

Kim JH et al. · 2017

Researchers exposed C57BL/6 mice to 835 MHz RF-EMF at an SAR of 4.0 W/kg for 12 weeks, then analyzed the hippocampus and brain stem. Several autophagic genes were significantly upregulated only in the hippocampus and not in the brain stem. Transmission electron microscopy revealed an increase in the number of autophagosomes and autolysosomes in the hippocampal neurons of exposed mice.

Changes in numbers and size of synaptic vesicles of cortical neurons induced by exposure to 835 MHz radiofrequency-electromagnetic field.

Kim JH, Kim HJ, Yu DH, Kweon HS, Huh YH, Kim HR. · 2017

Researchers studied the effects of RF-EMF exposure on synaptic vesicles in the cortical neurons of mice. C57 BL/6 mice were exposed to 835 MHz RF-EMF at 4.0 W/kg SAR for 5 hours daily. The density of synaptic vesicles was significantly decreased in the presynaptic boutons of cortical neurons after exposure. The expression of synapsins I/II genes and proteins was also significantly decreased in exposed mice.

Histopathological, immunohistochemical, and stereological analysis of the effect of Gingko biloba (Egb761) on the hippocampus of rats exposed to long-term cellphone radiation.

Gevrek F. · 2017

Rats were divided into three groups — Control, EMR, and EMR+Egb761 — and the EMR groups were exposed to cellphone radiation at 0.96 W/kg SAR for one month. In the EMR group, apoptotic proteins (Bax, Acas-3) increased and the anti-apoptotic protein Bcl-2 decreased, along with a reduction in total granule and pyramidal cell counts. Rats that also received Egb761 showed decreased Bax and Acas-3, increased Bcl-2, fewer TUNEL-stained apoptotic cells, and a higher total viable cell number.

Evaluation of the potential of mobile phone specific electromagnetic fields (UMTS) to produce micronuclei in human glioblastoma cell lines.

Al-Serori H et al. · 2017

Researchers investigated whether UMTS radiofrequency signals cause micronucleus formation and other anomalies such as nuclear buds and nucleoplasmatic bridges in human glioblastoma cell lines. The experiments were conducted with human glioblastoma cell lines, U87 with wild-type p53 status and U251 with mutated p53 status, exposed to SAR doses of 0.25, 0.50, and 1.00 W/kg. The researchers found no evidence for induction of micronuclei or other anomalies, but observed apoptosis at the highest dose in U251 cells.

Effects of 15 Hz square wave magnetic fields on the voltage-gated sodium and potassium channels in prefrontal cortex pyramidal neurons.

Zheng Y, Dou JR, Gao Y, Dong L, Li G. · 2017

Researchers isolated cortical pyramidal neurons from Kunming mice and exposed them to 15 Hz, 1 mT square wave magnetic fields. Sodium currents, transient potassium currents, and delayed rectifier potassium currents were recorded using the whole-cell patch clamp method. Magnetic field exposure depressed channel current densities and altered the activation kinetics of sodium and potassium channels, and the inactivation properties of INa and IA were also altered.

Influence of extremely low frequency magnetic fields on Ca2+ signaling and double messenger system in mice hippocampus and reversal function of procyanidins extracted from lotus seedpod.

Zhang H et al. · 2017

Researchers investigated the influence of a 50 Hz, 8 mT extremely low frequency magnetic field, applied 4 hours per day for 28 days, on calcium ion signaling in the hippocampus of mice. Exposure increased levels of Gi protein, IP3, DAG, PKA, PKC beta, PP2B, and intracellular calcium, while decreasing CaMK II and PKC alpha. ELF-MF exposure also decreased the level of brain-derived neurotrophic factor (BDNF), which the researchers described as playing a key role in hippocampal neuronal cell death. Oral administration of procyanidins from lotus seedpod, especially at 90 mg per kg, significantly recovered these changes and nearly reached normal levels.

Effect of extremely low frequency electromagnetic field on brain histopathology of Caspian Sea Cyprinus carpio.

Samiee F, Samiee K. · 2017

Researchers examined how extremely low frequency electromagnetic field (ELF-EMF) exposure at 50 Hz affected brain tissue in Cyprinus carpio, a common carp species from the Caspian Sea. A total of 200 healthy fish were divided into a sham-exposed group and an experimental group exposed to five different magnetic field intensities (0.1, 1, 3, 5, and 7 mT) at two different exposure times (0.5 and 1 h). Exposure caused severe histopathological changes in the brain at field intensities of 3 mT or higher, leading to brain necrosis, with field intensity and duration of exposure identified as key parameters in causing lesions.

Static Magnetic Field Stimulation Enhances Oligodendrocyte Differentiation and Secretion of Neurotrophic Factors.

Prasad A et al. · 2017

Researchers stimulated human oligodendrocyte precursor cells (OPCs) with a moderate intensity static magnetic field (0.3 T) for two weeks, two hours per day. The study investigated the genomic effects of static magnetic field exposure on oligodendrocyte differentiation and neurotrophic factor secretion. Enhanced myelination capacity of the stimulated oligodendrocytes was validated using a dorsal root ganglion microfluidics chamber platform.

Occupational exposure to extremely low-frequency magnetic fields and risk for central nervous system disease: an update of a Danish cohort study among utility workers.

Pedersen C et al. · 2017

Researchers investigated risks for several central nervous system diseases among 32,006 men employed at 99 utility companies that supplied Denmark with electricity during 1900–1993. The cohort was followed during 1982–2010, and cases were identified in the Danish National Patient Registry. For the highest exposure level of 1.0 µT or more, incidence rate ratios of 1.44, 1.78, 1.40 and 1.34 were observed for dementia, motor neurone disease, multiple sclerosis and epilepsy, respectively. Risk for Parkinson disease was lower among workers exposed to ≥0.1 µT compared with the Danish population (IRR 0.81, 95% CI 0.67–0.97).

Effects of extremely low frequency electromagnetic fields on morphine analgesia and tolerance in rats.

Ozdemir E et al. · 2017

Researchers used 78 adult male Wistar albino rats to investigate whether extremely low frequency electromagnetic fields affect morphine analgesia and tolerance. Rats were exposed to a 50 Hz magnetic field for 30 minutes each day for 15 days, and morphine tolerance was induced with high-dose morphine (50 mg/kg) for 3 days. In rats exposed to the magnetic field, the analgesic effect of morphine (5 mg/kg) was significantly higher than in the non-exposed morphine group, and morphine-tolerant animals exposed to the field also showed significantly higher analgesia than tolerant rats without field exposure.

Extremely low frequency magnetic field protects injured spinal cord from the microglia- and iron-induced tissue damage.

Dey S, Bose S, Kumar S, Rathore R, Mathur R, Jain S. · 2017

Researchers performed complete transection of the spinal cord at the T13 level in male Wistar rats, then exposed them to a magnetic field at 50 Hz and 17.96 µT for 2 hours daily for 8 weeks. Compared to injured rats that received no magnetic field, injured rats that received the magnetic field showed significant improvement in locomotion. Histology, immunohistochemistry, and flow cytometry revealed significant reductions in lesion volume, microglia, macrophage, collagen tissue, and iron content, along with higher vascular endothelial growth factor expression in the magnetic field group.

Effects of A 60 Hz Magnetic Field of Up to 50 milliTesla on Human Tremor and EEG: A Pilot Study.

Davarpanah Jazi S, Modolo J, Baker C, Villard S, Legros A. · 2017

Ten healthy volunteers were exposed to 11 MF conditions (60 Hz, 0 to 50 mTrms, 5 mTrms increments) while physiological tremor and EEG from motor and somatosensory brain regions were measured. Exposure had no significant effect on any physiological tremor characteristics, and no significant EEG effects were observed for electrodes C1, C3, C5 and CP1. At electrodes CP3 and CP5, a decreased mu-rhythm spectral power with increasing MF flux density was suggested, but this was not confirmed by Bonferroni corrected pairwise comparisons.

The effect of local extremely low frequency magnetic field on student sleepiness.

Ayoobi F, Shamsizadeh A, Shafiei SA. · 2017

This study investigated the impact of local extremely low frequency magnetic field (ELF-MF) on sleep and drowsiness in healthy young adults. Minimum reaction time after exposure increased significantly compared to before exposure (P = 0.03), while the mean of the SSS scores was no different compared to that before exposure.

Microwave radiation (2.45 GHz)-induced oxidative stress: Whole-body exposure effect on histopathology of Wistar rats.

Chauhan P, Verma HN, Sisodia R, Kesari KK. · 2017

Researchers exposed male Wistar rats to 2.45 GHz microwave radiation at a power density of 0.2 mW/cm2 for 2 hours a day for 35 days, then examined brain, liver, kidney, testis, and spleen. Significantly high levels of lipid peroxide were found in the liver (p < 0.001), brain (p < 0.004), and spleen (p < 0.006) of exposed rats. Histological changes were also observed in the brain, liver, testis, kidney, and spleen after whole-body microwave exposure, compared to the control group.

The antioxidant effect of Green Tea Mega EGCG against electromagnetic radiation-induced oxidative stress in the hippocampus and striatum of rats

Ahmed NA, Radwan NM, Aboul Ezz HS, Salama NA · 2017

Researchers exposed adult rats to EMR at a frequency of 900 MHz modulated at 217 Hz, with a power density of 0.02 mW/cm2 and SAR of 1.245 W/kg, and measured oxidative stress parameters in the hippocampus and striatum. EMR exposure produced disturbances in oxidant and antioxidant parameters in both brain regions. Green tea mega EGCG given at the beginning of EMR exposure for two and three months had more beneficial effect against EMR-induced oxidative stress than EGCG given after two months of exposure.