Figure 1. Attenuated retinal ganglion cell death after hydrogen sulfide preconditioning. A: Retinal ganglion cell (RGC) loss (RGC/mm²) presented as mean difference to individual control. Data are presented as mean±SD of eight experiments. Hydrogen sulfide (H₂S) preconditioning decreased RGC death by 41.5% compared to room air seven days after ischemia/reperfusion (I/R) injury (***p<0.001). B: RGC densities were not significantly different in controls exposed to room air or H₂S. Fluorogold (FG)-positive RGCs can be identified by morphological criteria (large round cell body, no processes, almost homogeneously labeled). In I/R treated eyes, many RGCs died and activated microglia cells (small cellular body, branching processes, inhomogeneously labeled; denoted with arrows in the extracts) stained FG-positive after RGC phagocytosis. H₂S preconditioning partly antagonized this effect, leading to significantly higher cell densities. The scale bar represents 100 µm.