Abstract
Filopodial dynamics are thought to control growth cone guidance, but the types and roles of growth cone dynamics underlying neural circuit assembly in a living brain are largely unknown. To address this issue, we have developed long-term, continuous, fast and high-resolution imaging of growth cone dynamics from axon growth to synapse formation in cultured Drosophila brains. Using R7 photoreceptor neurons as a model we show that >90% of the growth cone filopodia exhibit fast, stochastic dynamics that persist despite ongoing stepwise layer formation. Correspondingly, R7 growth cones stabilize early and change their final position by passive dislocation. N-Cadherin controls both fast filopodial dynamics and growth cone stabilization. Surprisingly, loss of N-Cadherin causes no primary targeting defects, but destabilizes R7 growth cones to jump between correct and incorrect layers. Hence, growth cone dynamics can influence wiring specificity without a direct role in target recognition and implement simple rules during circuit assembly.
Article and author information
Author details
Reviewing Editor
- Christine E Holt, University of Cambridge, United Kingdom
Publication history
- Received: August 7, 2015
- Accepted: October 26, 2015
- Accepted Manuscript published: October 29, 2015 (version 1)
- Version of Record published: January 5, 2016 (version 2)
Copyright
© 2015, Özel et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 3,198
- Page views
-
- 712
- Downloads
-
- 31
- Citations
Article citation count generated by polling the highest count across the following sources: Scopus, Crossref, PubMed Central.