Activation of GCR-signaling protects retinal ganglion against colchicine-mediated damage. Retinas were obtained from eyes that received consecutive daily injections of Dex (100ng/dose) or vehicle at P0, P1 and P2, 50 ng of colchicine at P3, Dex (100ng/dose) or vehicle at P4 and P5, and retinas were harvested at P14. Whole-mounts of the retina were labeled with antibodies to Brn3a (a). The scale bar indicates 50 μm. The histogram in panel b illustrates the mean (±SD; n≥5) percent change in Brn3a-positive ganglion cells per 40,000 μm2 of central, temporal, nasal or dorsal regions of retina. Significance of difference (*p<0.05) was determined by using Mann-Whitney U test.