Neurophysiologic effects at low level 1.8 GHz radiofrequency field exposure: a multiparametric approach on freely moving rats.

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.