estimation of toxicant effects; uncertainties in the degree ofmeasurement equivalence when tests are transported into differentlanguages and cultures; and the influence of normal developmentalbrain changes on the domain of functioning and the stability andpredictive validity of test scores. Conclusion: The field of environ-mental epidemiology is nearing a stage where a formal set of meth-odological and reporting guidelines could be developed to help in thedesign of future studies, as has been done with clinical trials, studiesof diagnostic assessment tools, and medical epidemiological studies.Supported by Cefic-LRI.

doi:10.1016/j.ntt.2010.04.037

NBTS37Weight-of-the-evidence assessment in neurodevelopmentalepidemiology: A plea for consistency

Michael GoodmanEmory University, Atlanta, GA, United States

doi:10.1016/j.ntt.2010.04.038

NBTS38Effects of domoic acid on early visual memory in infants from theCoastal Cohort

Kimberly Granta, Tom Burbachera, Sparkle Robertsb, Lynn Grattanb

aUniversity of Washington, Seattle, WA, United StatesbUniversity of Maryland, Baltimore, Maryland, United States

The effect of domoic acid on infant growth and development is anemerging public health issue but largely unexplored in the scientificarena. The Coastal Cohort study is an on-going prospective investiga-tion focused on the cognitive effects of domoic acid (DA) exposure inNative Americans living on the coast of Washington State. As part ofthis larger epidemiological study, 35 infants were tested on the FaganTest of Infant Intelligence© (FTII). Fetal exposure to DAwas estimatedthrough maternal dietary reports and environmental monitoring datafrom local beaches. The Fagan Test of Infant Intelligence is a cognitivetest that measures attention and visual recognition memory and hasbeen successfully used in field and laboratory studies to examine theneurobehavioral consequences of prenatal exposure to environmen-tal contaminants. In this study, infants in the Coastal Cohort, rangingin age from nine to twelve months, completed all ten problems on theFTII. The preliminary results from this study show that infants in thiscohort are, as a group, performing well within the normal range onthis test (mean infant novelty preference across all study sites=62.9%, sd=6.4). The range of novelty scores from 51.4% to 78.2%demonstrates there were strong individual differences in perfor-mance. Preliminary results suggest a moderate trend for lowermemory scores in infants with putative DA exposures of 2 ppm to4 ppm compared with exposures of .5 ppm (65.0% vs 61.3%, p<.09).Maternal estimates of exposure are still being calculated as we moveforward with the analyses.

doi:10.1016/j.ntt.2010.04.039

NBTS39Acute postnatal exposure to the pentaBDE commercial mixtureDE-71 at low doses (5 or 15 mg/kg/day) does not produce learningor attention deficits in rats

Lori DriscollColorado College, Colorado Springs, CO, United States

Polybrominated diphenyl ethers (PBDEs) are additive flameretardants used in the manufacturing of furniture, household ap-pliances and many textiles. Human PBDE exposure occurs primarilythrough inhalation and ingestion; in infants, high doses are ingestedin breast milk. Previously in our laboratory, learning deficits wereobserved in rats exposed to DE-71, a commercial PBDE mixture, at adose of 30 mg/kg/day during the second postnatal week. The purposeof the current study was to determine if this effect is observed atlower doses of DE-71. Rats received one of three daily oral treatmentdoses of DE-71 (0 mg/kg, 5 mg/kg, or 15 mg/kg) from postnatal days6–12 and were tested as adults on variations of a 5-choice serialreaction time task. Learning was measured by acquisition rate of theinitial visual discrimination task, in which the rats were trained tomake a nosepoke to the randomly selected port in which a visual cueappeared. Attention was assessed by measuring the rats' responseaccuracy and error types when the visual cues were made brief andunpredictable. No significant effect of DE-71 treatment group wasfound on any of the dependent variables, suggesting that the in-vestigated doses were below threshold to induce impairment in thesetasks. Therefore, future research should investigate doses between15 mg/kg and 30 mg/kg in order to determine the critical levelsrequired to generate learning impairments.

doi:10.1016/j.ntt.2010.04.040

NBTS40Gene-toxicant interactions: Developmental PBDE effects on thebehavioral phenotype of the Mecp2-308 Rett syndromemouse model

Mari Golub, Roxanne Vallero, Joanne Suarez, Ta Tram Anh,Pessah Isaac, Berman Robert, LaSalle JanineUniversity of California Davis, Davis, CA, United States

Gene-environment interactions may play a role in childhoodneurobehavioral disease. Chronic low dose developmental exposureto the flame retardant PBDE-47 (0.03 mg/kg d, oral administration tothe dam from 30 day prior to mating to weaning of the litter) wasstudied for interaction with the behavioral phenotype of the Mecp2-308mouse, a transgenic model for Rett syndrome. Infant, juvenile andadult tests were included in the offspring behavioral test battery.During the dosing period, PBDE-47 influenced sensorymaturation andseparation-induced vocalizations but later tests were not affected.Interactions between genotype and PBDE occurred on some testsimportant to the intellectual and social phenotype associated withreduced MECP2 expression in humans, namely infant vocalizationduring social isolation, juvenile social preference, and adult learningandmemory. The interactions occurred primarily for the heterozygousMecp2308/+ female rather than in the hemizygous Mecp2308/y malessuggesting a greater sensitivity of the phenotype to environmentaltoxicants in females. Supported by NIH ES015171.

doi:10.1016/j.ntt.2010.04.041

NBTS 2010 Abstract 507