Inhibitory Interactions and Columnar Inputs to an Object Motion Detector in Drosophila
Mehmet F Keleş1, Ben J Hardcastle1, Carola Städele1
1University of California, Los Angeles, Department of Integrative Biology and Physiology, 610 Charles Young Drive East, Los Angeles, CA 90095-7239, USA.
Cell Reports
|February 21, 2020
Summary
Small object motion detectors in flies, like LC11, have suppressed responses to background motion. This suppression is mediated by T2 and T3 neurons, not GABA-A receptors, revealing new insights into fly visual processing.
Area of Science:
- Neuroscience
- Animal Behavior
- Sensory Systems
Background:
- Direction-selective T4/T5 cells in flies are crucial for optic-flow processing and locomotion control.
- The precise input circuitry and computational mechanisms underlying feature detection in lobula projection neurons remain unclear.
Purpose of the Study:
- To investigate the input circuitry and computational basis of the small object motion detector LC11 in the fly lobula.
- To determine how LC11's responses are modulated by local background motion and identify the underlying neural mechanisms.
Main Methods:
- Electrophysiological recordings and genetic manipulations in Drosophila melanogaster.
- Characterization of LC11 neuron responses to small objects and background motion.
- Investigation of the role of GABA-A receptors and T2/T3 neuron inputs in LC11 function.
Main Results:
- LC11 neuron responses to small moving objects are suppressed by local background motion.
- GABA-A receptors in LC11 sculpt responses to small objects but do not mediate background motion rejection.
- Columnar T2 and T3 neurons, insensitive to wide-field motion, innervate LC11 and are critical for suppressing background motion effects.
Conclusions:
- The rejection of background motion by the LC11 small object detector is primarily mediated by inhibitory inputs from T2 and T3 neurons.
- This circuitry allows for specialized detection of small objects amidst complex visual environments, distinct from the T4/T5 cell pathways.
- LC11 and its inputs represent a distinct computational module for salient object detection in fly vision.
