Circulation of the cerebrospinal fluid (CSF) contributes to body axis formation and brain development. Here, we investigated the unexplained origins of the CSF flow bidirectionality in the central canal of the spinal cord of 30 hpf zebrafish embryos and its impact on development. Experiments combined with modeling and simulations demonstrate that the CSF flow is generated locally by caudally-polarized motile cilia along the ventral wall of the central canal. The closed geometry of the canal imposes the average flow rate to be null, explaining the reported bidirectionality. We also demonstrate that at this early stage, motile cilia ensure the proper formation of the central canal. Furthermore, we demonstrate that the bidirectional flow accelerates the transport of particles in the CSF via a coupled convective-diffusive transport process. Our study demonstrates that cilia activity combined with muscle contractions sustain the long-range transport of extracellular lipidic particles, enabling embryonic growth.
The data enabling to plot all graphs for figures and supplemental videos have been deposited to the Dryad Digital Repository doi:10.5061/dryad.4mj3pv1.The full MATLAB script can be found on Github https://github.com/wyartlab/eLife_2019_OriginAndRole
Data from: Origin of bidirectionality of cerebrospinal fluid flow and impact on long range transport between brain and spinal cordDryad Digital Repository, doi:10.5061/dryad.4mj3pv1.
- Francois Gallaire
- Claire Wyart
- Martin Carbo-Tano
- Claire Wyart
- Yasmine Cantaut-Belarif1
- Martin Carbo-Tano
- Claire Wyart
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Animal experimentation: All procedures were performed on zebrafish embryos before 2 days post fertilization in accordance with the European Communities Council Directive (2010/63/EU) and French law (87/848) and approved by the Brain and Spine Institute (Institut du Cerveau et de la Moelle épinière).
- Julien Vermot, Institut de Génétique et de Biologie Moléculaire et Cellulaire, France
© 2020, Thouvenin 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.
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