Mice deficient for Tnfα have greater retinal ganglion cell loss from crush than wild-type mice. (A) Wild-type and Tnfα -/- mice were subjected to optic nerve crush and analyzed for total retinal ganglion cell layer neuronal cells remaining at 7, 14, and 21 days after injury. The decline in cell numbers was not statistically significant between the two genotypes at 7 days, but at 14 and 21 days Tnfα -/- mice had significantly more cell loss (*P <0.001 for both time points). (B,C) Retinal whole mounts from wild-type and Tnfα -/- mice were analyzed for Caspase 3 (CASP3) activation 3 and 5 days after optic nerve crush. At 3 days, Tnfα -/- mice has a significantly greater number of CASP3+ cells (*P <0.05), but by 5 days the difference between the two genotypes was no longer significant. Results are presented at mean ± SE (A,C); n ≥3 for all genotypes. Scale bar (B) =50 μm. GCL, ganglion cell layer.