Sensory-evoked potentials in rats chronically exposed to trichloroethylene: predominant auditory dysfunction

Sensory-evoked potentials (EPs) were studied in male Long-Evans and Fischer-344 rats in order to characterize the electrophysiological consequences of chronic inhalation exposure to trichloroethylene (TCE). Groups of ten Long-Evans rats were exposed to air or 1600 ppm or 3200 ppm TCE for twelve weeks and evaluated periodically with a multisensory test battery. Brainstem auditory-evoked response (BAER) amplitudes were depressed by TCE, whereas somatosensory and visual potentials remained normal. The effects on BAERs, which varied with tone intensity and frequency, suggested that TCE causes a predominantly high-frequency hearing loss. Comparable effects were obtained in both strains of rats and were like those previously observed following exposure to toluene.