Age-dependent changes in fibroblast growth factor 2 (FGF-2) expression in mouse cerebellar neurons

Fibroblast growth factor 2 (FGF-2) is a neurotrophic factor that regulates many neuronal functions and survival. We have characterised FGF-2 expression immunohistochemically in the cerebellum of young (4 months) and old (22 months) mice. About half of the population of the granule cells (GC), and all Purkinje cells (PC) expressed FGF-2 in all folia of the cerebellum at both ages. FGF-2 showed differential intracellular localization: predominantly localised to the nuclei of GC and present mainly in the cytosol of PC. There was a statistically significant (P = 0.0028) reduction in the number of FGF-2-positive GC in the cerebella of old (41.3 +/- 0.91%) compared to young (48.5 +/- 1.67%) mice, whereas no statistically significant age-dependent difference occurred in the number of FGF-2 positive PC. These results indicate a possible role of FGF-2 in cerebellar ageing.