Repository logo
 

Imaging fictive locomotor patterns in larval Drosophila.


Change log

Authors

Pulver, Stefan R 
Bayley, Timothy G 
Taylor, Adam L 
Bate, Michael 

Abstract

We have established a preparation in larval Drosophila to monitor fictive locomotion simultaneously across abdominal and thoracic segments of the isolated CNS with genetically encoded Ca(2+) indicators. The Ca(2+) signals closely followed spiking activity measured electrophysiologically in nerve roots. Three motor patterns are analyzed. Two comprise waves of Ca(2+) signals that progress along the longitudinal body axis in a posterior-to-anterior or anterior-to-posterior direction. These waves had statistically indistinguishable intersegmental phase delays compared with segmental contractions during forward and backward crawling behavior, despite being ∼10 times slower. During these waves, motor neurons of the dorsal longitudinal and transverse muscles were active in the same order as the muscle groups are recruited during crawling behavior. A third fictive motor pattern exhibits a left-right asymmetry across segments and bears similarities with turning behavior in intact larvae, occurring equally frequently and involving asymmetry in the same segments. Ablation of the segments in which forward and backward waves of Ca(2+) signals were normally initiated did not eliminate production of Ca(2+) waves. When the brain and subesophageal ganglion (SOG) were removed, the remaining ganglia retained the ability to produce both forward and backward waves of motor activity, although the speed and frequency of waves changed. Bilateral asymmetry of activity was reduced when the brain was removed and abolished when the SOG was removed. This work paves the way to studying the neural and genetic underpinnings of segmentally coordinated motor pattern generation in Drosophila with imaging techniques.

Description

Keywords

calcium imaging, central pattern generator, intersegmental coordination, locomotion, neuroethology, Action Potentials, Animals, Brain, Calcium Signaling, Drosophila melanogaster, Ganglia, Invertebrate, Larva, Locomotion, Motor Neurons, Optical Imaging

Journal Title

J Neurophysiol

Conference Name

Journal ISSN

0022-3077
1522-1598

Volume Title

114

Publisher

American Physiological Society
Sponsorship
Wellcome Trust (105568/Z/14/Z)
S.R.P. was supported by a Newton International Fellowship (Royal Society) and a Junior Fellowship (Janelia Research Campus, Howard Hughes Medical Institute). T.G.B. was supported by a Medical Research Council (UK) PhD grant. J.B. was supported by a Henry Dale Fellowship (Royal Society and Wellcome Trust). M.B. was supported by the Isaac Newton Trust.