PUBLICATION

Developmental chlorpyrifos effects on hatchling zebrafish swimming behavior

Authors
Levin, E.D., Swain, H.A., Donerly, S., and Linney, E.
ID
ZDB-PUB-041004-11
Date
2004
Source
Neurotoxicology and teratology   26(6): 719-723 (Unknown)
Registered Authors
Donerly, Sue, Linney, Elwood
Keywords
Chlorpyrifos; Zebrafish; Behavior; Development; Swimming activity
MeSH Terms
  • Animals
  • Behavior, Animal/drug effects
  • Chlorpyrifos/toxicity*
  • Cholinesterase Inhibitors/toxicity
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Embryo, Nonmammalian/drug effects*
  • Embryo, Nonmammalian/embryology
  • Embryo, Nonmammalian/physiology
  • Habituation, Psychophysiologic/drug effects
  • Habituation, Psychophysiologic/physiology
  • Larva/drug effects*
  • Larva/growth & development
  • Motor Activity/drug effects*
  • Motor Activity/physiology
  • Physical Stimulation/methods
  • Reaction Time/drug effects
  • Reaction Time/physiology
  • Swimming/physiology
  • Zebrafish/embryology
  • Zebrafish/physiology*
PubMed
15451035 Full text @ Neurotoxicol. Teratol.
Abstract
Chlorpyrifos (CPF), a widely used organophosphate insecticide and potent acetylcholinesterase inhibitor, interferes with neurobehavioral development. Rat models have been key in demonstrating that developmental CPF exposure causes learning deficits and locomotor activity alterations, which persist into adulthood. Complementary nonmammalian models can be useful in determining the neurodevelopmental mechanisms underlying these persisting behavioral effects. Zebrafish (Danio rerio) with their clear chorion and extensive developmental information base provide an excellent model for assessment of molecular processes of toxicant-impacted neurodevelopment. We have developed methods for assessing spatial discrimination learning in adult zebrafish and have documented persisting effects of developmental CPF exposure on swimming activity and learning after low and high doses of CPF (10 and 100 ng/ml) administered to zebrafish embryos on Days 1-5 postfertilization (pf). In the current study, we developed methods for behavioral assessment of CPF exposure on swimming activity in newly hatched zebrafish. An equal area segmented annular grid (concentric circles divided into quadrants through the diameter) was made in a 16-mm diameter cylinder. The test area was placed on a heating device secured to an Olympus SZH10 dissecting scope stage. Zebrafish embryos were exposed to 10 ng/ml CPF, 100 ng/ml CPF, or vehicle control (25 microl/ml DMSO) (n=8-10/treatment group). Each treatment group was kept in a total volume of 25 ml of egg water (60 mg/ml Instant Ocean) including DMSO with or without CPF mixed to above dilutions in an incubator set at 28.5 degrees C. CPF dilutions or vehicle were changed daily with exposure ending on Day 5 pf. Testing of larval zebrafish was performed on Days 6 and 9 pf. The fish were placed in the test cylinder with 1.5 ml of egg H(2)O (28.5 degrees C). After a 2-min acclimation period, the swimming activity of the fish was measured for a 3-min testing session. The 100 ng/ml CPF dose caused significant slowing of swimming activity on Days 6 and 9 pf and had persisting effects of impairing spatial discrimination and decreasing response latency in adulthood. Developmental exposure to 10 ng/ml of CPF did not cause a significant change in locomotor activity during the period soon after hatching. CPF exposure during early development caused clear behavioral impairments detectable during the posthatching period. In a previous study, we found that early developmental CPF exposure caused behavioral alterations in zebrafish, which lasted throughout adulthood. The molecular mechanisms by which early developmental CPF exposure produces these behavioral impairments expressed in adulthood can now be studied in the zebrafish model.
Genes / Markers
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Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
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Orthology
Engineered Foreign Genes
Mapping