Effects of weak microwave fields amplitude modulated at ELF on EEG of symmetric brain areas in rats

Bioelectromagnetics. 1997;18(4):293-8. doi: 10.1002/(sici)1521-186x(1997)18:4<293::aid-bem1>3.0.co;2-y.


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 weak (0.1-0.2 mW/cm) microwave (MW, 945 MHz) field, amplitude-modulated 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 between control and exposure experiments were shown under these routines of data averaging. Significant elevations of EEG asymmetry in 10-14 Hz range 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. Under neither control nor pre- and postexposure conditions was this effect observed. These results are discussed with respect to interaction of MW fields with the EEG generators.

MeSH terms

  • Animals
  • Brain / physiology
  • Brain / radiation effects*
  • Electroencephalography / radiation effects*
  • Electromagnetic Fields / adverse effects*
  • Environmental Exposure / adverse effects
  • Male
  • Microwaves / adverse effects*
  • Rats
  • Sleep / physiology
  • Sleep / radiation effects
  • Somatosensory Cortex / physiology
  • Somatosensory Cortex / radiation effects