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

In Drosophila melanogaster, inhibiting campaniform sensilla proprioceptive feedback robustly impairs the ability to reach typical walking speeds, with deficits linked to altered stance kinematics.

• Why it matters: Proprioceptive force and load feedback are thought to stabilize motor control, but how campaniform sensilla signals shape adaptive walking and coordination in freely walking flies remains unclear.
• What they did: Using two-photon calcium imaging, the study showed campaniform sensilla activation induces activity in many leg muscles and can influence motor neuron activity. It then used transient optogenetic inhibition plus high spatiotemporal video tracking to test walking behavior, leg kinematics, and interleg coordination.
• The result: Campaniform sensilla inhibition robustly affects walking speed, and kinematic analysis suggests shorter stance amplitudes with long-lasting duration underlie the speed deficits. The phenotype also reveals impaired coordinated interleg stepping patterns and reduced postural control without proprioceptive force and load feedback.