title: Flash-, somatosensory-, and peripheral nerve-evoked potentials in rats perinatally exposed to Aroclor 1254.
abstract: Pregnant Long-Evans rats were exposed to 0, 1 or 6 mg/kg/day of Aroclor 1254 (A1254; Lot no. 124-191), a commercial mixture of polychlorinated biphenyls (PCBs), from gestation day (GD) 6 through postnatal day (PND) 21. At 128-140 days of age, male and female offspring were tested for visual-, somatosensory- and peripheral nerve-evoked potentials. The evoked responses increased in amplitude with larger stimulus intensities, and gender differences were detected for some endpoints. In contrast, developmental exposure to A1254 failed to significantly affect the electrophysiological measures. A subset of the animals were tested for low-frequency hearing dysfunction using reflex modification audiometry (RMA). An elevated threshold for a 1-kHz tone was observed, replicating previous findings of A1254-induced auditory deficits [Hear. Res. 144 (2000) 196; Toxicol. Sci. 45(1) (1998) 94; Toxicol. Appl. Pharmacol. 135(1) (1995) 77.]. These findings indicate no statistically significant changes in visual-, somatosensory- or peripheral nerve-evoked potentials following developmental exposure to doses of A1254 that produce behavioral hearing deficits. However, subtle changes in the function of the visual or somatosensory systems cannot be disproved.
authors.affiliation: Neurotoxicology Division, MD-74B, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA. herr.david@epamail.epa.gov
authors.forename: D W
authors.initials: DW
authors.lastname: Herr
authors.forename: J E
authors.initials: JE
authors.lastname: Graff
authors.forename: E C
authors.initials: EC
authors.lastname: Derr-Yellin
authors.forename: K M
authors.initials: KM
authors.lastname: Crofton
authors.forename: P R
authors.initials: PR
authors.lastname: Kodavanti
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001309:Auditory Threshold / Q000187:drug effects*; D020111:Chlorodiphenyl (54% Chlorine) / Q000633:toxicity*; D005073:Evoked Potentials, Somatosensory / Q000187:drug effects*; D005074:Evoked Potentials, Visual / Q000187:drug effects*; D005260:Female; D008297:Male; D010775:Photic Stimulation; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D020318:Rats, Long-Evans
chemical_list: D020111:Chlorodiphenyl (54% Chlorine)