The biological effects of millimetric waves systems, MMW (e.g. 5G communications, automotive radars, or crowd control systems, ADS) systems are still scarcely investigated. Hairless rats were exposed to 2 94GHz continuous wave (MMW, CW), under acute high power conditions (3sec at10kW/m ) and under 2 environmental/professional lower power exposure (4 hours a day, for 5 days a week, for 6 months at 10mW/cm ). It was found that the 94 GHz acute exposure provoked the disappearance of the epidermis upper corneal layers and the increase of the inammatory gene expression SOCS-3 after 3Hrs. Besides, neither histological nor genetic modication could be observed after chronic 94 GHz exposure and after an acute and a chronic capsaicin exposure. Conclusions :After a powerful acute exposition a thermal effect is observable, associated with a localized inammatory response. After chronic, low power exposition, an hypoalgesia effect was found, possibly related with an increase in brain plasticity. Mechanistically, the hypothesis is based on low noise stimulation of thermal pain receptors at subthreshold level. Conversely, neither inammation nor no direct change in was found.
HF radiofrequency exposure and/or the presence of carbon nanotubes (CNT) induce modifications to the structure and dynamics of model membranes. These modifications were investigated by multinuclear NMR methods in various phospholipid membrane systems. CNTs were found to spontaneously integrate into the superficial layer of membranes at low temperatures; they did not interact with the terminal methyl group of the chains. The local order was increased from C10 to the plateau region of the acyl chain, whereas the local order in the depth was not significantly modified. A specific implication of the choline headgroup was found, resulting in an overall rigidification when CNTs were present. While low-level, athermal radiofrequency exposure in the HF band alone had no significant effect on membrane structure or dynamics, it did partially reverse the consequences of CNT interactions with the membrane by producing a new membrane structure, possibly consistent with gel-or cubic-phase formation.
Deleterious effects on healthcare and particularly disruption of the cholinergic system have been reported after exposure to radiofrequency field at low power density. This work presents a 72 hours multiparametric study, where cholinergic system was investigated using a neurochemical, electrophysiological and physiological approaches. Free moving rats were exposed 24 hours to RF GSM signal at 1.8 GHz at low power density (1.2 and 9 W/m(2)). Acetylcholine (ACh) release in the hippocampus was simultaneously monitored using the microdialysis technique, electroencephalogram (EEG), electromyogram (EMG) and subcutaneous temperature. A spectral analysis of EEG was also performed and sleep stages were determined. After experimental time, the animals were sacrificed and a NMR study was performed on lipid brain extract. No significant parameters modification was observed under RF exposure. The only significant difference was the lack of increase in time spent in REM sleep, the third day, for the 1.2 W/m(2) group. This observation appeared difficult to explain and could not be reasonably related with RF exposure. Similarly, the NMR study also failed to show any effect of RF.
We present a neurochemical, electrophysiological and physiological study on freely moving rats. During 3 days, we have simultaneously monitored acetylcholine (ACh) release in the hippocampus using the microdialysis technique, electroencephalogram (EEG), electromyogram (EMG) and subcutaneous temperature. A spectral analysis of EEG was performed and sleep stages were determined. Energy ratio in the delta (0-4 Hz), slow theta (4-6.5 Hz) and fast theta (6.5-9 Hz) band was calculated. Sleep stages were quantified using an automatic staging method.The circadian cycle of these parameters was observed. Waking, body temperature and ACh release presented synchronized cycles with close acrophases.The relationship between the central cholinergic system and the other parameters is discussed. The influence of handling on the measured parameters, as well as possible artifacts linked to the use of neostigmine in the microdialysis method are considered. Attention was focused on the cholinergic control of EEG theta rhythms. (c) 2005 Elsevier B.V. All rights reserved.
