AbstractBy using an antibody to goldfish glial fibrillary acidic protein (GFAP), the reaction of goldfish optic nerve to injury has been studied by immunoblotting and immunohistochemical methods. Goldfish optic nerve, which normally lacks GFAP immunoreactivity (Nona et al.:Glia, 2:189–200, 1989), expresses GFAP following injury. This immunoreactivity, which is observed as early as 10 days after crush and which is still evident at 30 days after crush, all but disappears by 150 days after crush. Since it is well established that functional restoration of synaptic connections and the recovery of vision takes place in goldfish following optic nerve injury, our results indicate that reactive astrocytes do not represent an impediment to regeneration in goldfish visual syste