Figure 6.

Impact of CNTN on early Na_v channel cluster formation in the optic nerve at P8. (a and d) immunostainings of sections of WT (a) and CNTN‐KO (D) P8 mice optic nerve show the presence of Na_v clusters (green), Caspr clusters (red) in the WT (a) but not the KO condition (d), and myelin (MBP⁺, white). Both heminodes (blue arrowhead) and prenodal clusters (white arrowhead) are observed in the WT (a). Scale bars: 10 μm. (b and r) immunostainings of sections of WT (B) and KO (E) P8 mice optic nerve show clusters with Na_v (green), AnkyrinG (red) and Nfasc (white) that are colocalizing (plot profile). Scale bars: 2 μm. (c) Quantification of the proportion of the different structures (i.e., nodes, heminodes, and prenodes or isolated Na_v clusters) from images of Na_v and Caspr immunostainings on WT optic nerve at P8 (n = 6 mice, 87 images) and P9 (n = 4 mice, 40 images). (f) Quantification of density of Na_v clusters per 10,000 μm² for the WT and the KO at P8, mean ± SEM, student t‐test, ns. Values were obtained from n = 6 WT and n = 5 KO animals, with 10 to 20 images acquired per animal