Active antennal movements in Drosophila can tune wind encoding

Area of Science:

• Neuroscience
• Sensory Biology
• Insect Behavior

Background:

• Insects utilize antennae for diverse sensory inputs, including olfaction, audition, and mechanosensation.
• Active antennal movements are crucial for sensory processing, yet the neural control of antennal motor systems in Drosophila melanogaster remains poorly understood.

Purpose of the Study:

• To investigate the neural mechanisms controlling antennal movements in Drosophila melanogaster in response to sensory stimuli.
• To identify genetic tools for manipulating antennal motor systems and dissect their role in active sensing.

Main Methods:

• Deep learning was employed to quantify antennal movements in response to wind and odor stimuli.
• Characterization of antennal muscles and identification of genetic driver lines targeting antennal motor neurons.
• Optogenetic inactivation of motor neurons and muscles to assess their contribution to antennal movements and sensory encoding.

Main Results:

• Drosophila exhibit distinct slow adaptive and fast flicking antennal movements in response to wind, but not apple cider vinegar odor.
• Four muscles in the first antennal segment control antennal movements, with identified genetic lines providing access to motor neurons and muscles.
• Optogenetic inactivation revealed that antennal motor neurons influence active movements with different temporal dynamics.
• Activation of motor neurons and muscles modulates the gain and acuity of wind direction encoding via antennal displacement.

Conclusions:

• This study elucidates the neural control of antennal movement in Drosophila, highlighting the role of specific muscles and motor neurons.
• Active antennal positioning in Drosophila appears to be a mechanism for optimizing the precision of wind sensory information processing.