FIGURE 5.

Optic nerve axon loss. (A) Impact-vehicle mice showed a significant 21.8% loss of optic nerve axons compared to sham mice. Treatment with 5 mg/kg raloxifene yielded partial rescue, with only a 7.4% reduction in optic nerve axons, such that axon abundance was significantly greater than for the impact-vehicle mice and only trended toward being significantly different from sham (p = 0.084). With raloxifene at 10 mg/kg, axon abundance was again significantly greater than in the impact-vehicle mice and indistinguishable from that in sham mice. Errors bars are SEMs. Animal numbers: 21 sham-vehicle mice, 25 impact-vehicle mice, 21 impact-ral5 mice, and 13 impact-ral10 mice. (B–E) High-magnification views of the optic nerve in sham-vehicle, impact-vehicle, impact-ral5, and impact-ral10 mice. The density of axons is obviously lower in the image from the impact-vehicle mouse, and glial cells occupy relatively more space than in the image from the sham mouse. The asterisk in C marks the nucleus of a glial cell. By contrast, axon density in the images from the impact-ral5 and impact-ral10 mice appears similar to that in the image from the sham mouse. Scale bar in (E) applies to (B–E).