Long Term Effects of Early Embryonic Ethanol Exposure, on Behavioural Performance and Learning in Zebrafish, Danio rerio

Background: Fetal alcohol syndrome (FAS) is a devastating disorder whose mechanisms may be best investigated using animal models. Here we present a novel zebrafish FAS model to investigate the effects of low to moderate alcohol exposure during early development on learning. Methods: At 24-hours postfertilization zebrafish embryos were exposed to low doses of ethanol (external concentrations = 0.00, 0.25, 0.50, 0.75 and 1.00% vol/vol) for a very short duration (2 hours). Upon adulthood associative learning in the zebrafish was tested in a plus maze. Results: This exposure led to no gross anatomical abnormalities or increased morbidity or mortality. Overall activity was not significantly affected by embryonic ethanol exposure. A trend towards a dose-dependent decrease in learning and memory performance was observed. Conclusions: We suggest that zebrafish will be an appropriate model with which one can analyze the behavioural effects of embryonic alcohol exposure and the mechanisms of the ensuing abnormalities.MAS