posted on 2019-08-30, 13:59authored byJR Sternberg, AE Prendergast, L Brosse, Y Cantaut-Belarif, O Thouvenin, A Orts-Del'Immagine, L Castillo, L Djenoune, S Kurisu, JR McDearmid, P-L Bardet, C Boccara, H Okamoto, P Delmas, C Wyart
Defects in cerebrospinal fluid (CSF) flow may contribute to idiopathic scoliosis. However, the mechanisms underlying detection of CSF flow in the central canal of the spinal cord are unknown. Here we demonstrate that CSF flows bidirectionally along the antero-posterior axis in the central canal of zebrafish embryos. In the cfap298tm304 mutant, reduction of cilia motility slows transport posteriorly down the central canal and abolishes spontaneous activity of CSF-contacting neurons (CSF-cNs). Loss of the sensory Pkd2l1 channel nearly abolishes CSF-cN calcium activity and single channel opening. Recording from isolated CSF-cNs in vitro, we show that CSF-cNs are mechanosensory and require Pkd2l1 to respond to pressure. Additionally, adult pkd2l1 mutant zebrafish develop an exaggerated spine curvature, reminiscent of kyphosis in humans. These results indicate that CSF-cNs are mechanosensory cells whose Pkd2l1-driven spontaneous activity reflects CSF flow in vivo. Furthermore, Pkd2l1 in CSF-cNs contributes to maintenance of natural curvature of the spine.
Funding
We thank Prof. Brian Ciruna for the Tg(β-actin:Arl13b-GFP) transgenic line and Prof. Rebecca Burdine for the cfap298tm304 mutant line, Sophie Nunes-Figueiredo, Natalia Maties, Bogdan Buzurin, and Monica Dicu for fish care, Steven Knafo for advice on human spinal deformities, Vincent Guillemot amd François-Xavier Lejeune for statistical analysis, Annick Prigent for assistance with Alizarin red staining, the histology and imaging ICM-Quant platforms of the ICM, and members of the Wyart Lab for critical feedback (https://wyartlab.org). This work was supported by an ERC Starting Grant “Optoloco” #311673, the HFSP Program Grants #RGP0063/2014 and #RGP0063/2018, the Michelin Corporate Foundation, Mr. Pierre Belle, and a BBSRC program grant BB/N010140/1 to J.R.M. J.R.S. was supported by the Ecole des Neurosciences de Paris. A.E.P. was supported by an EMBO long-term fellowship (ALTF 549–2013) and a Research in Paris grant from the Mairie de Paris.
Data and MATLAB scripts used for analysis are available from the authors upon request.
Supplementary Information accompanies this paper at https://doi.org/10.1038/s41467-018-06225-x.