G-CSF protects RGCs after optic nerve transection. Subcutaneous daily injection of G-CSF (B, C) dose-dependently attenuated RGC apoptosis after optic nerve transection when compared to vehicle injection (A, C). 14 days after optic nerve transection reduction in RGC loss was statistically significant at a dose of 40 μg/kg bodyweight s.c. when the first injection was performed approximately 2 h after the optic nerve transection. Starting G-CSF injection one day before axotomy (40 μg/kg + 1 d) resulted in a slight, but non-significant increase in RGC numbers compared to treatment starting after the lesion. Panels (A) and (B) show an eccentricity at one half of the retinal radius. * p < 0.05 (20 vs. 40 μg/kg bodyweight); ** p < 0.01 (40 μg/kg or 40 μg/kg + 1 d vs. vehicle); n.s. = not significant. Data are given as mean ± S.E.M.