title: Assessing locomotor activity in larval zebrafish: Influence of extrinsic and intrinsic variables.
abstract: The U.S. Environmental Protection Agency is evaluating methods to screen and prioritize large numbers of chemicals for developmental toxicity. We are exploring methods to detect developmentally neurotoxic chemicals using zebrafish behavior at 6 days of age. The behavioral paradigm simultaneously tests individual larval zebrafish under both light and dark conditions in a 96-well plate using a video tracking system. We have found that many variables affect the level or pattern of locomotor activity, including age of the larvae, size of the well, and the presence of malformations. Some other variables, however, do not appear to affect larval behavior including type of rearing solution (10% Hank's vs. 1:3 Danieau vs 60 mg/kg Instant Ocean vs 1× and 1:10× EPA Moderately Hard Water). Zebrafish larval behavior using a microtiter plate format may be an ideal endpoint for screening developmentally neurotoxic chemicals, but it is imperative that many test variables be carefully specified and controlled.
authors.affiliation: Integrated Systems Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U. S. Environmental Protection Agency, Research Triangle Park, NC 27711, United States. Padilla.Stephanie@epa.gov
authors.forename: S
authors.initials: S
authors.lastname: Padilla
authors.forename: D L
authors.initials: DL
authors.lastname: Hunter
authors.forename: B
authors.initials: B
authors.lastname: Padnos
authors.forename: S
authors.initials: S
authors.lastname: Frady
authors.forename: R C
authors.initials: RC
authors.lastname: MacPhail
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D004625:Embryo, Nonmammalian / Q000002:abnormalities* / Q000187:drug effects*; D057166:High-Throughput Screening Assays / Q000379:methods; D007814:Larva / Q000187:drug effects; D009043:Motor Activity / Q000187:drug effects*; D015999:Multivariate Analysis; D017440:Photoperiod; D013723:Teratogens / Q000633:toxicity*; D014116:Toxicology / Q000379:methods; D014741:Video Recording; D015027:Zebrafish / Q000002:abnormalities / Q000196:embryology*
chemical_list: D013723:Teratogens