You are here:
A MULTIFACETED, MEDIUM-THROUGHPUT APPROACH FOR DETECTING AND CHARACTERIZING DEVELOPMENTAL NEUROTOXICITY USING ZEBRAFISH.
Citation:
COWDEN, J., B. K. PADNOS, D. L. HUNTER, R. C. MACPHAIL, K. F. JENSEN, AND S. J. PADILLA. A MULTIFACETED, MEDIUM-THROUGHPUT APPROACH FOR DETECTING AND CHARACTERIZING DEVELOPMENTAL NEUROTOXICITY USING ZEBRAFISH. Presented at Society of Toxicology, Seattle, WA, March 16 - 20, 2008.
Impact/Purpose:
To address the EPA's need to prioritize hundreds to thousands of chemicals for testing, we are developing a rapid, cost-effective in vivo screen for developmental neurotoxicity using zebrafish (Danio rerio), a small freshwater fish with external fertilization.
Description:
To address the EPA's need to prioritize hundreds to thousands of chemicals for testing, we are developing a rapid, cost-effective in vivo screen for developmental neurotoxicity using zebrafish (Danio rerio), a small freshwater fish with external fertilization. Zebrafish embryos develop rapidly (3-4 days) in a clear chorion, allowing visual inspection throughout development. The screen consists of four general endpoints: death, teratology, nervous system structure and locomotor activity. All maintenance and testing were conducted in a 96-well microtiter plate format at 26°C. Zebrafish embryos were exposed to a range of ethanol concentrations (0.25% to 4%) from 6 hours to 5-days post fertilization (dpf). At 2dpf the nervous systems of some embryos were examined by whole mount anti-acetylated α-tubulin staining; at 6dpf, additional larvae were assessed for death, terata, and locomotor activity. The LC50 at 2dpf was approximately 2.6% ethanol; this value dropped to 1.6% ethanol by day 6. The most common terata were edema, microcephaly, and micropthalmia. Embryos exposed to ethanol concentrations below 0.75% did not show an incidence of teratogenic effects different from control embryos. Whole mount anti-acetylated α-tubulin staining at 2dpf revealed a dose-dependent decrease in retinotectal projections. These effects occurred at ethanol doses well below teratogenic levels. Exposure to ethanol below teratogenic doses also elicited changes in locomotor activity. Collectively, these findings demonstrate the potential utility of this multifaceted screen for developmental neurotoxicity using zebrafish larvae.