Fig. 4. Removal of PSA causes a defasciculation in the posterior commissure. (A-F) The posterior commissure (pc) in zebrafish embryos at 32 hpf after injections into the ventricle at 20 hpf, labelled with acetylated 
-tubulin antibodies. (A,B) In buffer-injected control embryos the pc crosses the midline (dotted line) in one thick bundle. (C,D) In endo N-injected embryos, axons of the pc split into several thin bundles that cross the midline (arrowheads). (E,F) In PSA-polymer injected embryos, the fasciculated growth pattern of the pc is not affected. (A-F) All images are confocal images, dorsal view, rostral at the top. Scale bar: 10 µm.
