Optogenetic Control of Free-flight Manuvers in Drosophila Melanogaster
1 Max Planck Institute for Neurobiology of Behavior u2013 caesar
The flight of Drosophila melanogaster consists of two distinct phases: straight flight interrupted by rapid and sharp turns, called ‘saccades.’ These saccades can be categorized into escape saccades, triggered by external stimuli, and exploratory saccades, initiated by internal mechanisms. Understanding the neuronal basis of these distinct flight behaviors is crucial for elucidating how Drosophila navigates its environment. Previous research into the neuronal control of flight behavior in Drosophila has primarily focused on descending neurons (DNs)—a few hundred pairs of neurons that integrate information from the central brain and transform it into motor commands sent to the ventral nerve cord. Advances in identifying and modifying specific neurons have led to the discovery of specific DNs involved in flight control and saccades. However, these studies have been primarily conducted on tethered flies. While tethered preparations provide unrivaled access to the fly’s brain, they are significantly limited by restricting its movement and proprioceptive feedback. To overcome these limitations and study the role of DNs under more natural conditions, we have designed and constructed a free-flight arena with closed-loop optogenetic activation capabilities. We selected a subset of DNs known to be correlated with saccades and activated them mid-flight, either bilaterally or unilaterally, using stochastic labeling techniques. High-speed, high-resolution video recordings of these maneuvers allowed us to discriminate different flight behaviors in greater detail. By combining free-flight conditions with advanced neuronal manipulation techniques, our study provides new insights into the neural mechanisms underlying flight control and saccade generation in Drosophila.