Fig. 6

IOP treatment accelerates the resolution of microglia/macrophages in the ON and OT. A. Overview of the presence of inactive and reactive microglia/macrophages (arrow heads) after ONC in the injured ON and OT as detected with the 4C4 antibody. B–C. Magnification of the inactive ramified form (red) and the reactive amoeboid form of microglia/macrophages (red, arrowhead) in ON and OT of the sham operated and ONC side, respectively. Nuclei are stained with DAPI (blue). Scale bar — 5 µm. D. and H. Quantification of the area covered by the microglia/macrophages in the proximal ON and OT in UC and IOPp fish at 4, 7 and 10 dpi, respectively. Data represent mean ± SEM (n = 3–6 animals/group). **p < 0.005 and ***p < 0.0001 by unpaired t-test, compared to UC at the same time point. E.–G. and I.–K. Immunofluorescent detection of activated microglia/macrophages in the proximal ON and the OT at 4, 7 and 10 dpi. The site of crush is marked by a yellow dotted line. At 4 dpi microglia/macrophages are more densely packed in the proximal ON in the IOPp group compared to the UC group (indicated by arrowhead in panel E). At 7 and 10 dpi less microglia/macrophages are present in the OT of the IOPp group compared to the respective UC group (indicated by arrowheads in panels J and K). Scale bar — 100 µm. For all panels: UC—untreated control, IOPp—iopanoic acid pretreated for 2 weeks, S—sham operated optic nerve, X—optic nerve crushed, ON—optic nerve, OT—optic tectum.