Developmental chlorpyrifos effects on hatchling zebrafish swimming behavior

Area of Science:

• Neuroscience
• Toxicology
• Developmental Biology

Background:

• Chlorpyrifos (CPF) is an organophosphate insecticide known to disrupt neurobehavioral development.
• Rat models show developmental CPF exposure leads to persistent learning deficits and altered locomotor activity.
• Nonmammalian models are valuable for understanding the neurodevelopmental mechanisms of these persistent effects.

Purpose of the Study:

• To develop methods for assessing CPF's impact on larval zebrafish behavior.
• To investigate the persisting effects of developmental CPF exposure on swimming activity and learning in zebrafish.
• To establish zebrafish as a model for studying CPF-induced neurodevelopmental toxicity.

Main Methods:

• Zebrafish embryos were exposed to 10 ng/ml or 100 ng/ml CPF from Days 1-5 postfertilization.
• Swimming activity of larval zebrafish was measured on Days 6 and 9 postfertilization using a segmented annular grid.
• Spatial discrimination learning and response latency were assessed in adult zebrafish.

Main Results:

• A 100 ng/ml CPF dose significantly slowed swimming activity in larval zebrafish.
• Developmental exposure to 100 ng/ml CPF resulted in persistent spatial discrimination deficits and decreased response latency in adulthood.
• A 10 ng/ml CPF dose did not significantly alter locomotor activity in the posthatching period.

Conclusions:

• Early developmental exposure to CPF causes detectable behavioral impairments in larval zebrafish.
• Zebrafish serve as a robust model for studying the molecular mechanisms of CPF-induced neurobehavioral alterations.
• CPF exposure during critical developmental windows can lead to long-lasting behavioral deficits.