Glial cell localization of acidic fibroblast growth factor-like immunoreactivity in the optic nerve of young adult and aged mammals.

The number of axons in the optic nerve decreases with age and this degeneration is greater in patients suffering from Alzheimer's disease. Alterations in the role of neurotrophic factors could lead to this degeneration. Acidic fibroblast growth factor (aFGF)-like immunoreactivity was examined by indirect immunofluorescence on cryostat sections incubated with a rabbit polyclonal antiserum specific for aFGF. Staining was observed by photonic microscopy on optic nerves of Wistar rats (1- to 25-month-old), bovine animals (0.5- to 7-year-old) and normal human adults (24-, 34-, 54- and 84-year-old). In the three species studied, the results show that (1) glial cells were stained in the nuclear region and (2) aFGF-like immuno-reactivity was present over a large age span in adult subjects. Endogenous aFGF may have trophic effects on retinal ganglion cells and their axons throughout the adult life span.