Terra D. Irons
US EPA, Room B-254
Research Triangle Park, NC 27711
Tel: (919) 541-0506
Fax: (919) 541-0717
Education
Doctorate of Philosophy
Curriculum in Toxicology
Research Advisor: Stephanie Padilla
Academic Advisor: n/a
Date of Matriculation: 2006
Bachelor of Science in Chemistry
Norfolk State University, Norfolk, VA, 2006
Publications and Recent Abstracts
Irons, TD, MacPhail, R, Hunter, DL, and Padilla, S. (2008) “Drug effects on the locomotor activity of larval zebrafish.” University of North Carolina at Chapel Hill Curriculum in Toxicology Annual Retreat. Chapel Hill, NC. (Also to be presented at Aquatic Animal Models of Human Disease meeting and SOT)
Dissertation
“Neurotoxicity of Acetylcholinesterase Inhibitors on the Developing Zebrafish Embryo.”
Advisor: Stephanie Padilla
As part of an effort to develop a rapid in vivo screen for EPA’s prioritization of toxic chemicals, we have begun to characterize the locomotor activity of zebrafish (Danio rerio) larvae and the effects of prototypic drugs. Zebrafish larvae (6-7 days post-fertilization) were individually maintained in 96-well microtiter plates at 26°C and under a 14:10 light:dark cycle with lights on at 0830 hr. Drugs included nominal (non-lethal) concentrations of ethanol (1 – 4% v/v), d-amphetamine sulfate (0.08 – 20 μM) and cocaine (0.2 – 50 μM). For each drug, all doses and controls were present on each plate. A total of 12 – 32 larvae were exposed to each concentration. Locomotor activity was assessed using a Noldus video activity monitor and Ethovision 3.1 software to track each animal under either visual light or dark (infrared) conditions for up to 90 minutes post-dosing. Each of the three chemicals produced dose-related changes in activity. In general, low concentrations increased activity while higher concentrations decreased activity; similar patterns have been obtained in rodent tests of motor activity. These results indicate that very young zebrafish are sensitive to centrally active drugs, and that drug challenges may be conducted in a convenient, microtiter plate format.