A Descending Neuron Correlated with the Rapid Steering Maneuvers of Flying Drosophila
To navigate through the world, animals must stabilize their path against disturbances and change direction to avoid obstacles and to search for resources [1 ; 2]. Locomotion is thus guided by sensory cues but also depends on intrinsic processes, such as motivation and physiological state. Flies, for example, turn with the direction of large-field rotatory motion, an optomotor reflex that is thought to help them fly straight [3; 4 ; 5]. Occasionally, however, they execute fast turns, called body saccades, either spontaneously or in response to patterns of visual motion such as expansion [6; 7 ; 8]. These turns can be measured in tethered flying Drosophila [ 3; 4 ; 9], which facilitates the study of underlying neural mechanisms. Whereas there is evidence for an efference copy input to visual interneurons during saccades , the circuits that control spontaneous and visually elicited saccades are not well known. Using two-photon calcium imaging and electrophysiological recordings in tethered flying Drosophila, we have identified a descending neuron whose activity is correlated with both spontaneous and visually elicited turns during tethered flight. The cell's activity in open- and closed-loop experiments suggests that it does not underlie slower compensatory responses to horizontal motion but rather controls rapid changes in flight path. The activity of this neuron can explain some of the behavioral variability observed in response to visual motion and appears sufficient for eliciting turns when artificially activated. This work provides an entry point into studying the circuits underlying the control of rapid steering maneuvers in the fly brain.
© 2017 Elsevier Ltd. Received 26 August 2016, Revised 19 January 2017, Accepted 2 March 2017, Available online 6 April 2017Published: April 6, 2017. We would like to thank Ainul Huda and Peter Weir for the image of the R56G08-Gal4 line; Shigehiro Namiki for information about Gal4 lines labeling descending neurons; and Gaby Maimon, Theodore Lindsay, and Peter Weir for comments on the manuscript. This work was supported by the Raymond and Beverly Sackler Foundation (B.S.), the Paul G. Allen Family Foundation (M.H.D.), and the National Institute of Neurological Disorders and Stroke of the NIH under award U01NS090514 (M.H.D). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. Author Contributions: Conceptualization, B.S. and M.H.D.; Methodology, B.S. and I.G.R.; Investigation, B.S. and I.G.R.; Formal Analysis, B.S. and I.G.R.; Writing – Original Draft, B.S. and M.H.D.; Writing – Review & Editing, B.S., I.G.R., and M.H.D.; Funding Acquisition, B.S. and M.H.D.; Supervision, M.H.D. Accession Numbers: Data reported in this manuscript have been deposited at the Dryad Digital Repository: http://dx.doi.org/10.5061/dryad.n7v41.
Supplemental Material - mmc1.pdf
Supplemental Material - mmc2.mp4
Supplemental Material - mmc3.mp4
Supplemental Material - mmc4.mp4
Accepted Version - nihms865361.pdf
||667.8 kB||Preview Download|
||244.0 kB||Preview Download|