Learning and Memory in a Drosophila Model of Fetal Alcohol Syndrome

Fetal Alcohol Syndrome (FAS) is caused by alcohol consumption during pregnancy and affects 1-3 live births per 1000 in the U.S. FAS individuals exhibit phenotypes that include decreased survival, developmental delay, growth deficits, abnormal response to ethanol exposure, behavioral problems, and cognitive deficits. These cognitive deficits are among the most socially consequential aspects of FAS. We have previously shown that rearing Drosophila melanogaster on ethanol-treated food during larval development results in FAS-like phenotypes. This is consistent with studies that have demonstrated homology in Drosophila and vertebrate responses to ethanol. Cognitive performance, however, has not been studied in ethanol-reared flies. To expand the FAS model, this study introduces cognitive assessment of ethanol-reared flies via learning and memory assays. We hypothesize that ethanol-reared flies will exhibit defects in learning and memory relative to control flies. From the battery of established protocols used in Drosophila to study genes and neurological systems that mediate cognitive processes, we have chosen assays that test olfactory learning and memory, which are highly conserved between arthropods and vertebrates. Classical conditioning is used to teach flies to associate an odor with a reward; flies’ preference for this odor is then tested in a t-maze to assess learning. Memory is then assayed over a period of hours or days. Assuming confirmation of the primary hypothesis, these assays will be used, with the UAS-Gal4 system, to examine effects of ethanol rearing on specific neurons or neural structures (e.g. the mushroom bodies), with the goal of identifying and characterizing mechanisms underlying pathologies.