Tracking Sugar-Elicited Local Searching Behavior in Drosophila

Our study employs Drosophila as a genetic model to identify key stimulus input pathways in searching behavior. This approach aims to reveal the neural networks triggering local search behavior, enhancing understanding beyond what's known in honeybees and ants, potentially applying to humans. Drosophila is a powerful genetic model system.

Understanding foraging behavior in flies led to the identification of novel circuits that were not known earlier in any other model system, not only neurons. How internal state act on these circuits to regulate physiology and behavior has been studied recently. Our research explores the potential evolutionary link between fly local search and honeybee dance communication as hypothesized by Vincent Dethier.

We found similarities between the two behavior indicating shared neural and molecular mechanisms. This suggests that Drosophila could be used as a model system to study honeybee dance. In combination with neurogenetic manipulation and original imaging, this paradigm presents a powerful and promising approach.

Our protocol does not involve any expensive materials and can be custom made in the lab. It's easy and efficient to compare many parameters using user friendly software that generates reproducible and robust data. Our study focuses on identifying brain circuits that intersect various behavioral pathways in foraging, including feeding, sleep regulation, and decision making.

These are conserved across species, and we are investigating how these brain structures interact and regulate multiple behaviors simultaneously. To begin, collect adult male Drosophila flies within 12 hours from emerging, place them on standard fly media for 48 hours at 25 degrees Celsius. Starve the flies of food, but retain their access to water.

To calculate the food starvation of two day old flies place 15 to 20 flies in a vial with soaked tissue paper at the bottom. Transfer the starved flies individually into small tubes. Place the tubes near the illuminated arena, surrounded by a white polyvinyl chloride pipe.

Use the camera software to focus on the arena. Place about two microliters of sugar solution in the arena center. Now, slowly invert the micro centrifuge tube with a single fly over the sugar drop.

Film the 2D position of the arena with an overhead camera. Finally, analyze the trajectory of each fly to determine its search behavior. Sugar intake in starved flies led to a local search with a meandering path and loops.

The unfed flies, however, did not initiate a search, but instead escaped the arena. The parameters of search, that is path length, stay time, meander, and number of returns were significantly lower in the unfed flies.