title: Developmental PCB exposure increases susceptibility to audiogenic seizures in adulthood.
abstract: Developmental exposure to polychlorinated biphenyls (PCBs) causes auditory deficits. Thus, we recently conducted a study to investigate if developmental PCB exposure would exacerbate noise-induced hearing loss in adulthood. Unexpectedly, some PCB-exposed rats exhibited seizure-like behaviors when exposed to loud noise. Therefore, we conducted the current experiment to determine if adult rats perinatally exposed to PCBs are more susceptible to audiogenic seizures when tested in a standard audiogenic seizure paradigm. Adult male and female rats exposed to PCBs during gestation and lactation (0, 1, 3 or 6 mg/kg/day) and previously tested in the noise-induced hearing loss study were presented with a 100 dB noise stimulus. If they did not exhibit clonus in response to the 100 dB noise, they were exposed to a 105 dB stimulus 24-48 h later. This was followed by an 110 dB stimulus 24-48 h later if they did not exhibit clonus at 105 dB. Female and male rats exposed to either 3 or 6 mg/kg PCBs exhibited a significantly higher incidence of audiogenic seizures, shorter latency to onset of seizures, and greater severity of seizures compared to controls. Thyroxine measured in littermates at weaning was significantly lower in all PCB groups compared to controls, suggesting a potential mechanism for the increased incidence of audiogenic seizures. This is the first study to show that developmental PCB exposure increases the susceptibility to audiogenic seizures in adulthood.
authors.affiliation: Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Poon
authors.affiliation: Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Suren B
authors.initials: SB
authors.lastname: Bandara
authors.affiliation: Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61802, USA; Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL 60801, USA.
authors.forename: Jont B
authors.initials: JB
authors.lastname: Allen
authors.affiliation: Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL 60801, USA. Electronic address: rnhaag@illinois.edu.
authors.forename: Renee N
authors.initials: RN
authors.lastname: Sadowski
authors.affiliation: Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL 60801, USA; Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, Urbana, IL 61802, USA. Electronic address: schantz@illinois.edu.
authors.forename: Susan L
authors.initials: SL
authors.lastname: Schantz
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D000831:Animals, Newborn; D015331:Cohort Studies; D004198:Disease Susceptibility / Q000139:chemically induced; D004305:Dose-Response Relationship, Drug; D004785:Environmental Pollutants / Q000633:toxicity*; D020195:Epilepsy, Reflex / Q000139:chemically induced*; D005260:Female; D008297:Male; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced*; D011863:Radioimmunoassay; D011897:Random Allocation; D051381:Rats; D020318:Rats, Long-Evans; D011930:Reaction Time / Q000187:drug effects; D012727:Sex Characteristics; D018709:Statistics, Nonparametric; D013974:Thyroxine / Q000378:metabolism
chemical_list: D004785:Environmental Pollutants; D011078:Polychlorinated Biphenyls; D013974:Thyroxine
keywords: Audiogenic seizures; Hearing loss; PCBs