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Neurobehavioral evaluations of rats gestationally exposed to gasoline vapors
Citation:
Moser, V. C., Kathy Mcdaniel, T. Beasley, AND P. Bushnell. Neurobehavioral evaluations of rats gestationally exposed to gasoline vapors. Presented at Annual Neurobehavioral Teratology Society Meeting, Baltimore, MD, June 23 - 27, 2013.
Impact/Purpose:
This abstract will be presented at the Annual Neurobehavioral Teratology Society meeting, June 23-27, 2013, Baltimore, MD
Description:
As the US fuel supply is moving towards blends with higher ethanol levels, there are questions regarding effects of these fuel vapors in the developing fetus. As part of a project evaluating gasoline-ethanol blends of different proportions. we included an evaluation of inhaled pure gasoline vapor (no ethanol). Pregnant Long-Evans rats (n=1 8/concentration) were exposed to gasoline vapors (0, 3000, 6000, 9000 ppm total hydrocarbons) for 6 hr/day in whole-body inhalation chambers from gestational day 9 to 20. An additional group (cage controls, n=12) was included to evaluate the influence of inhalation chamber housing during pregnancy. After birth, offspring were allocated to various neurological, immunological, and metabolic tests. In the present study, one male and one female from each of ten litters per treatment group were used for behavioral testing that included locomotor activity (preweaning, postweaning, adult), overall evaluation using a functional observational battery (FOB: postweaning, adult), and cognitive function in a Morris water maze (place learning followed by match-to-sample, or working memory: adult). Comparison of the cage and air control groups revealed few significant differences across all tests, but only an effect on body weight was consistent: cage controls (both sexes) weighed more, beginning as young adults and persisting through the rest of testing. Effects of gasoline-exposed rats were compared only to the air control. There were no differences in body weight/growth or motor activity at any age. A decrease in one sensorimotor test in the FOB (tail pinch: adult males only, all treatment groups same) was observed. In the Morris water maze, treated rats showed decreased pathlength across days during place training (6000 ppm males only) and increased latency and pathlength on a single day during the working memory trials (9000 ppm females). There were no differences in other learning or memory parameters, swim speed, or latency to reach a visible platform. Taken together these sporadic and nonsystematic findings do not suggest treatment-related adverse outcomes on these behavioral measures following exposure to gasoline vapors during gestation. This is an abstract of a proposed presentation and does not reflect US EPA policy.