Figure 5.

Neuroprotection by active immunization with Cop-1. Immunization with Cop-1 in CFA, boosted with oral administration of the antigen, leads to protection against secondary degeneration. Immediately after mild optic nerve injury, rats were immunized s.c. with PBS in CFA or Cop-1 in CFA. For assessment of secondary degeneration, the neurotracer dye 4-Di-10-Asp was applied to the optic nerve distal to the site of injury 2 weeks after crush injury, and 5 days later the rats were killed and their retinas were excised and flat-mounted. Labeled (surviving) RGCs, from four fields located at approximately the same distance from the optic disk in each retina, were counted under the fluorescence microscope. The neuroprotective effect of Cop-1 immunization compared with that of PBS injection was significant (P < 0.01, Student's t test). The results are the summary of two experiments, each carried out with 5–6 rats in each group.