Electrocorticogram changes caused by subchronic lead treatment of rats

Male Wistar rats were treated per os through gavage for 4, 8 and 12 weeks by 80.0, 160.0 and 320.0 mg/kg lead in form of lead acetate. The changes of certain parameters (mean frequency, mean amplitude, ECoG index-the ratio of the slow and fast bands, power spectrum of the frequency bands) of the electrocorticogram (ECoG) recorded from the primary somatosensory, visual and auditory centres of anaesthetized rats were analysed. The data show that all investigated parameters had dose- and time-dependent changes: increased mean frequencies accompanied by decreased mean amplitudes and ECoG-indices. These changes were significant only at the highest, or at the two higher dose groups by the end of the experiment. The data suggest that subchronic, low-level exposure of lead can affect the integrated electrophysiological function of the brain.