Characterizing serotonin in the fruit fly brain [abstract]

Abstract

The biogenic amines serotonin (5-HT) and dopamine (DA) have been implicated in the formation of place memories in Drosophila melanogaster. However, stronger evidence exists in support of 5-HT as the more essential factor in mediating this process. My project focused on characterization of the serotonergic system in fly brains using immunocytochemistry. I probed for 5-HT using a monoclonal antibody and studied its co-localization with neurons expressing GFP driven by either Ddc-Gal4 or DdcThGal80. In an ongoing process, I have so far been able to count 31(+/- 3) 5-HT immunoreactive neurons per hemisphere, 10-15 of which also express GFP. This research works toward a well characterized 5-HT system which can corroborate the various genetic and pharmacological manipulations that are currently used to examine the effects of serotonin on memory formation. I investigated the effects of one of these pharmacological agents, alpha-methyl tryptophan, in addition to the immuno-labeling experiments. After a three-day treatment with the drug, flies showed a lower but not significant decrease in place learning performance as measured using the heat box.