locust flight muscle activity and body orientation in
TRANSCRIPT
Created by Peter Downing – Educational Media Access and Production © 2011
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Locusts (Locusta migratoria) are ideal model
systems to study complex behaviours, such as flight
responses to objects approaching on a collision
course. Thus far, flight muscle activity, wing
kinematics and aerodynamic forces of locusts have
been recorded during collision avoidance
behaviour and measured from rigidly-tethered
locusts flying in open-loop conditions. However,
loosely-tethered flying locusts are capable of
changing orientation in response to looming stimuli
within a single wing beat, and generate avoidance
responses within a single downstroke. To better
understand neural control of flight steering, we
placed a loosely-tethered flying locust inside an
existing flight simulator, and presented visual
stimuli of objects moving along complex
trajectories.
INTRODUCTION
METHODS
RESULTS
Muscle activity and corresponding physiological changes
Acknowledgements
Funding provided by the Natural Science and Engineering Research Council
of Canada, the Canada Foundation for Innovation and the University of
Saskatchewan.
References
[1] McMillan, G. A., Loessin, V., & Gray, J. R. (2013). The Journal of
experimental biology, 216(17), 3369-3380. [2] Silva, A. C., McMillan, G. A.,
Santos, C. P., & Gray, J. R. (2015). Journal of neurophysiology, 113(1), 218-
231. [3] Santer, R. D., Simmons, P. J., & Rind, F. C. (2005). Journal of
Comparative Physiology A, 191(1), 61-73. [4] McMillan, G. A., & Gray, J. R.
(2012). Journal of neurophysiology, 108(4), 1052-1068.
SUMMARY
ACKNOWLEDGEMENTS &
REFERENCES
Locust flight muscle activity and body orientation in response to
objects moving along complex trajectoriesSinan Zhang and John R. Gray, Dept. Biology, University of Saskatchewan
Stimuli-independent EMG frequency change
Behavioural responses during collision avoidance
• Locusts generate steering behaviour
during collision avoidance, without
preference in directions
• Changes in flight direction can be
reflected by the latency between
bilateral flight muscle spikes
• Within a flow field background, wing
beat frequency decreased during object
approach.
High speed camera recordings (1028 x 1028 pixels at 225fps) revealed the trajectory of locust flight during
collision avoidance. Images from two cameras, allowed 3D tracking of the locust position. A) 3D tracking
results showing the locust generating a maintained right turn while avoiding the disc coming from left at 45°.
B) Video capture from one camera, showing positions of the locust before and during avoidance behaviour;
C) Movement in x and z planes showing the overall right turn (changes in the y plane were minor). Time
aligned with TOC (Time of collision).
Time
A) Experimental setup, including visual stimuli projection, high
speed cameras and EMG recordings
C) Muscles recorded in this
experiment: M97 (forewing 1st
basalar), M99 (forewing subalar),
and M127 (hindwing 1st basalar)
B) Visual stimuli with flow
field background and tether
Loosely tethered locusts (n=3) were placed in the
center of a rear projection dome screen. Head-on air
flow (v=3m/s) was provided to maintain straight
flight. Visual stimuli (7 cm disc travelling at 3 m/s)
were projected from different directions (left 45°,
right 45°, 0°), with a flow field background (B).
Four markers on the tether monitored 3D body
position. (C) We recorded from 6 flight muscles
known to be associated with steering.Activity of 3 bilaterally paired steering muscles were also recorded during collision avoidance. Previous
studies have shown that the timing of these muscles are associated with attempted steering manoeuvres. A)
Sample EMG recordings (Left 45° looming); B) Bilateral latency increases indicating a steering behaviour;
C) EMG spike frequency (reflecting wing beat frequency) decreased as the disc approached.
A)
B)
C)
B)
Stimulus
generation
Stimulus frame
pulses
LCD
projector
Rear projection
dome screen
Data collection
and analysis
EMG Recordings
Time (s)
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req
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TOC
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B)
C)
A)
C)
LocustLocust
Looming
stimuliLooming
stimuli
Before During
A) 3D motion tracking of a locust avoiding a disc looming
from the left at 45°. The coordinate system is right-handed:
positive x to the right, positive y down, positive z to the front
(from the locust’s perspective of view)
Locust Tether
EMG spike frequency across all three types of
looming stimuli, displaying a stimuli-independent
decreasing trend over time.
A)Left 45°; B)Right 45°; C)0°.
Front (Z)
Down (Y)
Right (X)