Impact of Cerebral Radiofrequency Exposures on Oxidative Stress and Corticosterone in a Rat Model of Alzheimer’s Disease

Abstract

Background: Alzheimer's disease (AD) is the most common type of neurodegenerative disease leading to dementia. Several studies suggested that mobile phone radiofrequency electromagnetic field (RF-EMF) exposures modified AD memory deficits in rodent models.Objective: Here we aimed to test the hypothesis that RF-EMF exposure may modify memory through corticosterone and oxidative stress in the Samaritan rat model of AD. Methods: Long-Evans male rats received intracerebroventricular infusion with ferrous sulphate, amyloid-beta 1-42 peptide, and buthionine-sufloximine (AD rats) or with vehicle (control rats). To mimic cell phone use, RF-EMF were exposed to the head for 1 month (5 days/week, in restraint). To look for hazard thresholds, high brain averaged specific absorption rates (BASAR) were tested: 1.5 W/Kg (15 min), 6 W/Kg (15 min), and 6 W/Kg (45 min). The sham group was in restraint for 45 min. Endpoints were spatial memory in the radial maze, plasmatic corticosterone, heme oxygenase-1 (HO1), and amyloid plaques. Results: Results indicated similar corticosterone levels but impaired memory performances and increased cerebral staining of thioflavine and of HO1 in the sham AD rats compared to the controls. A correlative increase of cortical HO1 staining was the only effect of RF-EMF in control rats. In AD rats, RF-EMF exposures induced a correlative increase of hippocampal HO1 staining and reduced corticosterone. Discussion: According to our data, neither AD nor control rats showed modified memory after RF-EMF exposures. Unlike control rats, AD rats showed higher hippocampal oxidative stress and reduced corticosterone with the higher BASAR. This data suggests more fragility related to neurodegenerative disease toward RF-EMF exposures.

Manmade Electromagnetic Fields and Oxidative Stress—Biological Effects and Consequences for Health

“…In an Alzheimer's disease model, the stress marker cortisone and markers for oxidative stress in the brain of rats after RF-EMF exposure for 15 min (1.5, 6 W/kg) and for 45 min (6 W/kg) were measured, coincidental with the assessment of memory performance. While oxidative stress in the brain increased, cortisone levels and memory performance of RF-EMF-exposed Alzheimer's animals decreased markedly, an effect that was not observed in wildtype (devoid of Alzheimer) animals [63]. This study indicates that animals with a prior neurodegenerative condition might be more sensitive to RF-EMF exposure.…”

“…Thus, there is evidence that, at least in animal models, increased ROS production by EMF is associated with an impairment of cognitive abilities [51,52,[56][57][58][59][60]. Notably, RF-EMF exposure affected the memory performance of animals with neurodegenerative pre-damage of the brain (i.e., Alzheimer's disease model) more than in control wildtype animals [63], indicating an enhancement of conditions of impaired learning behavior by RF-EMF. In addition to such pre-existing conditions, other environmental or risk factors may also play a role in whether and to what extent oxidative stress due to EMF exposure occurs.…”

Evaluation of Inflammation by Cytokine Production Following Combined Exposure to Ultraviolet and Radiofrequency Radiation of Mobile Phones on 3D Reconstructed Human Skin In Vitro

“…Radiofrequency electromagnetic radiation belongs to the non-ionizing part of the electromagnetic spectrum, as all UV light greater than 100 nm wavelength are too weak to ionize molecules. Permissible RF levels proposed by ICNIRP (1998, 2020) are based on thermal effects only, whereas, a large number of publications suggest non-thermal effects, mainly through free radicals and oxidative stress [61][62][63][64][65][66]. Our work is based on the assumption of cooperative (additive), synergistic, or possible protective mechanisms of successive exposure to RF and UV, since UV radiation is able to induce adverse biological effects, per se.…”

Risk of Accidents or Chronic Disorders From Improper Use of Mobile Phones: A Systematic Review and Meta-analysis

“…Other studies [ 96 , 97 , 98 ] have reported physical harm caused by mobile phones, such as ear trauma, thigh injuries, electrical burns, and injuries caused by phone explosions. Furthermore, it has been suggested that electromagnetic fields generated by mobile phone may have long-term harmful effects, including an increase in infertility, Alzheimer disease, and other neurodegenerative diseases [ 99 ].…”