Godesberg, V. | Search bioRxiv

bioRxiv2026

Role of leg campaniform sensilla sensory feedback in Drosophila melanogaster adaptive walking

With the newly uncovered access to a genetic line labeling all campaniform sensilla in Drosophila melanogaster and the many insights gathered from larger insects, we analyzed the distribution and patterning of this class of proprioceptors throughout the fly nervous system and studied CS function in motor control. We demonstrate via two-photon calcium imaging microscopy that campaniform sensilla activation induces activity in many leg muscles, showing that these proprioceptive stimuli can influence motor neuron activity. We then dissected how the lack of these proprioceptive stimuli influence walking behavior, leg kinematics, and interleg coordination in freely-walking flies using transient optogenetic inhibition and video tracking with high spatiotemporal resolution. We show that CS inhibition robustly affects Drosophila melanogasters ability to reach their typical walking speeds. Detailed analysis of leg kinematic suggests that shorter stance amplitudes characterized by their long-lasting duration were behind the speed deficits. Dissecting this phenotype also revealed the inability to maintain coordinated interleg stepping patterns as well as postural control in absence of proprioceptive force and load feedback.

neuroscience↗

bioRxiv2023

Natural variability and individuality of walking behavior in Drosophila

Insects use walking behavior in a large number of contexts, such as exploration, foraging, escape and pursuit, or migration. A lot is known on how nervous systems produce this behavior in general and also how certain parameters vary with regard to walking direction or speed, for instance. An aspect that has not received much attention is if and how walking behavior varies across individuals of a particular species. To address this, we created a large corpus of kinematic walking data of many individuals of the fruit fly Drosophila. We only selected instances of straight walking in a narrow range of walking speeds to minimize the influence of these high-level parameters, aiming to uncover more subtle aspects of variability. Using high-speed videography and automated annotation we captured the positions of the six leg tips for thousands of steps and used principal components analysis to characterize the postural space individuals used during walking. Our analysis shows that the largest part of walking kinematics can be described by five principal components (PCs). Separation of these five PCs into a 2-dimensional and a 3-dimensional subspace was found to divide the description of walking behavior into invariant features shared across individuals and features that relate to the specifics of individuals; the latter features can be regarded as idiosyncrasies. We also demonstrate that this approach can detect the effects of experimental interventions in an unbiased manner and that general aspects of individuality, such as the average width of the individual walking posture, can be described. Summary statementThe kinematics of walking behavior in Drosophila can be decomposed into general aspects of motor output and idiosyncrasies of individual flies.

animal behavior and cognition↗