Localization of FGFR-1 in axotomized and peripheral nerve transplanted ferret retina

Retinal ganglion cells (RGCs) survive axotomy and regenerate their axons into the peripheral nerve graft in adult mammals. To understand the potential role of fibroblast growth factors (FGFs) in survival and regeneration of axotomized RGCs, we examined FGF receptor 1 (FGFR-1) localization in normal and PN grafted ferret retinas by immunohistochemistry in combination with retrograde labeling. Prominent expression of FGFR-1 was observed in outer plexiform layer and ganglion cell layer of normal ferret retina. In the ganglion cell layer, FGFR-1 immunoreactivity was detected in about 30% of RGCs, predominantly in large cells. In the PN grafted ferret retina, 90% of RGCs with regenerated axons expressed FGFR-1. Our findings suggest that FGFs may play an important role in the survival and axonal regeneration of RGCs of adult mammals.