Measurement of Reflexive Feeding Response in Drosophila

The ability to distinguish between food sources that are good and provide nutrients and those that are potentially dangerous is crucial to the survival of an organism. Here, we describe a taste assay that measures the reflexive feeding response to a given tastant. To examine taste preference for a soluble compound, an appetitive tastant is applied to the proboscis, and the proportion of proboscis extensions are recorded. This single-fly assay may be applied to adult Drosophila of any genetic background and facilities examination of the neural circuitry and molecular processes encoding the reflexive taste response. Furthermore, this assay requires few custom components and therefore can be easily established in laboratories with minimal expertise in the study of fly behavior.