Postnatal exposure to PCB 153 and PCB 180, but not to PCB 52, produces changes in measures of attention, activity level and impulsivity in outbred male Wistar Kyoto rats
Johansen, Espen Borgå; Knoff, Monica; Fonnum, Frode; Lausund, Per; Walaas, S. Ivar; Wøien, Grete; Sagvolden, Terje
Journal article, Peer reviewed, Journal article
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Date
2011Metadata
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Abstract
Background:
Polychlorinated biphenyls (PCBs) are a class of organic compounds that bioaccumulate due to their
chemical stability and lipophilic properties. Humans are prenatally exposed via trans-placental transfer, through
breast milk as infants, and through fish, seafood and fatty foods as adolescents and adults. Exposure has several
reported effects ranging from developmental abnormalities to cognitive and motor deficiencies. In the present
study, three experimental groups of rats were orally exposed to PCBs typically found in human breast milk and
then behaviorally tested for changes in measures of stimulus control (percentage lever-presses on the reinforcer-
producing lever), activity level (responses with IRTs > 0.67 s), and responses with short IRTs (< 0.67 s).
Methods:
Male offspring from Wistar Kyoto (WKY/NTac) dams purchased pregnant from Taconic Farms
(Germantown, NY) were orally given PCB at around postnatal day 8, 14, and 20 at a dose of 10 mg/kg body
weight at each exposure. Three experimental groups were exposed either to PCB 52, PCB 153, or PCB 180. A fourth
group fed corn oil only served as controls. From postnatal day 25, for 33 days, the animals were tested for
behavioral changes using an operant procedure.
Results:
PCB exposure did not produce behavioral changes during training when responding was frequently
reinforced using a variable interval 3 s schedule. When correct responses were reinforced on a variable interval
180 s schedule, animals exposed to PCB 153 or PCB 180 were less active than controls and animals exposed to
PCB 52. Stimulus control was better in animals exposed to PCB 180 than in controls and in the PCB 52 group.
Also, the PCB 153 and PCB 180 groups had fewer responses with short IRTs than the PCB 52 group. No effects of
exposure to PCB 52 were found when compared to controls.
Conclusions:
Exposure to PCBs 153 and 180 produced hypoactivity that continued at least five weeks after the last
exposure. No effects of exposure to PCB 52 were observed.
Publisher
BioMed Central
Except where otherwise noted, this item's license is described as © 2011 Johansen et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited.