EFFECTS OF WEAK MICROWAVE FIELDS AMPLITUDE-MODULATED AT ELF ON EEG OFSYMMETRICAL BRAIN-AREAS IN RATS

Averaged electroencephalogram (EEG) frequency spectra were studied in eight unanesthetized and unmyorelaxed adult male rats with chronically implanted carbon electrodes in symmetrical somesthetic areas when a w eak (0.1-0.2 mW/cm) microwave (MCV, 945 MHz) field, amplitude-modulate d at extremely low frequency (ELF) (4 Hz), was applied. Intermittent ( 1 min ''On,'' 1 min ''Off') field exposure (10-min duration) was used. Hemispheric asymmetry in frequency spectra (averaged data for 10 or 1 min) of an ongoing EEG was characterized by a power decrease in the 1 .5-3 Hz range on the left hemisphere and by a power decrease in the 10 -14 and 20-30 Hz ranges on the right hemisphere. No differences betwee n control and exposure experiments were shown under these routines of data averaging. Significant elevations of EEG asymmetry in 10-14 Hz ra nge were observed during the first 20 s after four from five onsets of the MW field, when averaged spectra were obtained for every 10 s. Und er neither control nor pre- and postexposure conditions was this effec t observed. These results are discussed with respect to interaction of MW fields with the EEG generators. (C) 1997 Wiley-Liss, Inc.