Measuring anesthetic resistance in Drosophila by VAAPR

Volatile anesthetics are compounds which are commonly used to induce a reversable loss of consciousness (LOC) in animals. The molecular mechanism of how anesthetics induce LOC is largely unknown. However, observations have been made which show that there are genetically-encoded traits which influence the effective concentration of anesthetics in the inducement of LOC. Despite this long-term observation, little progress has been made in identifying genes involved in anesthetic sensitivity. One reason for this is that many techniques to test anesthetic sensitivity are technically challenging and are inhibitory for high-throughput studies. Here we introduce a technique for testing volatiles and aerosols with positional recording (VAAPR), a method which allows for high-throughput testing of the effect of anesthetics and other aerosolized drugs using Drosophila. Using VAAPR we show that the enzyme phospholipase D (PLD) significantly shifts the concentration of diethyl ether, chloroform, and isoflurane needed to induce LOC in Drosophila. We also show that PLD is required for a paradoxical hyperactivity phenotype. We expect that this technique will allow for additional genes to be found which control anesthetic sensitivity as well as other behavioral phenotypes.