FIGURE 4

Glucocorticoids suppress glial bridges and axon regrowth. (A–H) Whole-mounted Tg(gfap:EGFP) zebrafish (lateral view) show spinal cord immunostaining for EGFP (green) and acetylated tubulin (axons, red) in uninjured controls (A,B), SCI followed by no treatment (C,E,G), and SCI with Dex treatment (D,F,H) for 24 and 72 h post SCI. Arrows indicate bipolar EGFP-positive glial bridges (C,E) and juxtaposed axons (C) that have entered the lesion at 24 h post SCI, but are absent with Dex treatments (D,F). Scale bar, 50 μm (A–H). (I) Quantification of the mean corrected total fluorescence intensity for axons (red lines) and ependymal glia (green lines) within 50 μm of the lesion center from no treatment controls (solid lines) and +Dex (dashed lines) relative to uninjured controls. Data show means ± SEM. ^∗p < 0.05; ^∗∗p < 0.01 compared to SCI no treatment; n = 10 zebrafish per time point in each condition. ^∗ and ^∗∗ are color coded to match corresponding data points.