Monitoring Calcium Levels in the Drosophila Brain Blood Barrier

The blood brain barrier (bbb) is a shielding layer composed of glial cells. Its job is to protect the brain from both toxins and metabolites capable of damaging neural function. In Drosophila melanogaster, it is known to also play an important role in male courtship behavior. Many studies have identified components that affect and regulate courtship. A recent discovery has shown that a dopamine receptor (D2R) in the bbb is required for courtship. Calcium is known to be a vital component in cell signaling and may play a role in male courtship. This study aims to explore the calcium response in the bbb and whether calcium response is dependent on the D2R. We used the Gal4-UAS system to conditionally express the calcium sensor NFAT (nuclear factors of activated T cells). When this sensor is activated by calcium it changes its conformation and regulates a process that generates green fluorescent protein (GFP) expression. Therefore, we can visualize GFP and make conclusions about the calcium concentrations in the bbb cells. We are using two approaches to observe GFP: direct observation of GFP and detection of GFP by immunohistochemistry. In my study I established a new system in the lab, I compared the NFAT response in flies that were mutations for D2R and wild type. The studies are still ongoing; our hypothesis is to find a decrease in GFP production in the mutants.