title: Latent cognitive effects from low-level polychlorinated biphenyl exposure in juvenile European starlings (Sturnus vulgaris).
abstract: Ecotoxicology research on polychlorinated biphenyl (PCB) mixtures has focused principally on short-term effects on reproduction, growth, and other physiological endpoints. Latent cognitive effects from early life exposure to low-level PCBs were examined in an avian model, the European starling (Sturnus vulgaris). Thirty-six birds, divided equally among 4 treatment groups (control = 0 µg, low = 0.35 µg, intermediate = 0.70 µg, and high = 1.05 µg Aroclor 1254/g body weight), were dosed 1 d through 18 d posthatch, then tested 8 mo to 9 mo later in captivity in an analog to an open radial arm maze. Birds were subject to 4 sequential experiments: habituation, learning, cue selection, and memory. One-half of the birds did not habituate to the test cage; however, this was not linked to a treatment group. Although 11 of the remaining 18 birds successfully learned, only 1 was from the high-dosed group. Control and low-dosed birds were among the only treatment groups to improve trial times throughout the learning experiment. High-dosed birds were slower and more error-prone than controls. Cue selection (spatial or color cues) and memory retention were not affected by prior PCB exposure. The results indicate that a reduction in spatial learning ability persists among birds exposed to Aroclor 1254 during development. This may have implications for migration ability, resource acquisition, and other behaviors relevant for fitness.
authors.affiliation: Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
authors.forename: Alexander R D
authors.initials: AR
authors.lastname: Zahara
authors.affiliation: School of Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
authors.forename: Nicole L
authors.initials: NL
authors.lastname: Michel
authors.affiliation: Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
authors.forename: Leanne M
authors.initials: LM
authors.lastname: Flahr
authors.affiliation: Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
authors.forename: Leanne E
authors.initials: LE
authors.lastname: Ejack
authors.affiliation: Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.|School of Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
authors.forename: Christy A
authors.initials: CA
authors.lastname: Morrissey
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001921:Brain / Q000187:drug effects / Q000502:physiology; D003071:Cognition / Q000187:drug effects*; D005260:Female; D007858:Learning / Q000187:drug effects; D008297:Male; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D046749:Starlings / Q000254:growth & development / Q000502:physiology
chemical_list: D011078:Polychlorinated Biphenyls
keywords: Avian behavior; Cognition; Neurodevelopment; Persistent organic pollutants; Thyroid hormone disruption