title: Cocaine self-administration in male and female rats perinatally exposed to PCBs: Evaluating drug use in an animal model of environmental contaminant exposure.
abstract: Polychlorinated biphenyls (PCBs) are ubiquitous environmental toxicants known to adversely impact human health.Ortho-substitutedPCBs affect the nervous system, including the brain dopaminergic system. The reinforcing effects of psychostimulants are typically modulated via the dopaminergic system, so this study used a preclinical (i.e., rodent) model to evaluate whether developmental contaminant exposure altered intravenous self-administration (IV SA) for the psychostimulant cocaine. Long-Evans rats were perinatally exposed to 6 or 3 mg/kg/day of PCBs throughout gestation and lactation and compared with nonexposed controls. Rats were trained to lever press for a food reinforcer in an operant chamber under a fixed-ratio 5 (FR5) schedule and later underwent jugular catheterization. Food reinforcers were switched for infusions of 250 μg of cocaine, but the response requirement to earn the reinforcer remained. Active lever presses and infusions were higher in males during response acquisition and maintenance. The same sex effect was observed during later sessions which evaluated responding for cocaine doses ranging from 31.25-500 μg. PCB-exposed males (not females) exhibited an increase in cocaine infusions (with a similar trend in active lever presses) during acquisition, but no PCB-related differences were observed during maintenance, examination of the cocaine dose-response relationship, or progressive ratio (PR) sessions. Overall, these results indicated perinatal PCB exposure enhanced early cocaine drug-seeking in this preclinical model of developmental contaminant exposure (particularly the males), but no differences were seen during later cocaine SA sessions. As such, additional questions regarding substance abuse proclivity may be warranted in epidemiological studies evaluating environmental contaminant exposures. (PsycINFO Database Record
authors.affiliation: Department of Psychology.
authors.forename: Mellessa M
authors.initials: MM
authors.lastname: Miller
authors.affiliation: Department of Psychological Science, University of North Georgia.
authors.forename: Abby E
authors.initials: AE
authors.lastname: Meyer
authors.affiliation: Division of Neurology, Cincinnati Children's Hospital Medical Center.
authors.forename: Jenna L N
authors.initials: JL
authors.lastname: Sprowles
authors.affiliation: Department of Psychology.
authors.forename: Helen J K
authors.initials: HJ
authors.lastname: Sable
mesh_terms: D000818:Animals; D003042:Cocaine / Q000008:administration & dosage*; D004195:Disease Models, Animal; D004298:Dopamine / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004781:Environmental Exposure / Q000009:adverse effects*; D004785:Environmental Pollutants / Q000008:administration & dosage / Q000009:adverse effects; D005260:Female; D008297:Male; D011078:Polychlorinated Biphenyls / Q000008:administration & dosage / Q000633:toxicity*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D020318:Rats, Long-Evans; D012054:Reinforcement, Psychology; D012646:Self Administration; D012737:Sex Factors
chemical_list: D004785:Environmental Pollutants; D011078:Polychlorinated Biphenyls; D003042:Cocaine; D004298:Dopamine