AbstractThe localization of acidic fibroblast growth factor (aFGF) in the male mouse brain was studied with biochemical and immunocytochemical techniques. Using two peptide-based aFGF antisera directed against independent epitopes, Western gel analysis of dissected brain demonstrated significant levels of aFGF immunoreactivity in the pons-medulla, hypothalamus and cerebellum. The cortex contained much less immunoreactivity. Consistent with the biochemical data, immunocytochemical analysis with the same two antisera demonstrated that aFGF immunoreactivity is localized in neuronal cell bodies in these regions. Numerous immunoreactive neurons were observed in the reticular formation of the pons and medulla, as well as in several other brainstem nuclei and areas. Immunoreactive neurons were also present in the lateral and medial hypothalamus, and some thalamic, subthalamic and epithalamic nuclei. In the basal ganglia, immunoreactive neurons were present in the amygdala and septum. Few intensely stained immunoreactive neurons were observed in the striatum, pallidum and neocortex. Limbic cortices contained more numerous immunoreactive neurons than neocortex. These results support the concept that aFGF is present in the brain, where it is heterogeneously distributed in neuronal cell bodies in regions involved in sensory, extrapyramidal motor, limbic and autonomic functions. The results are consistent with various neurotrophic, autogenic, and neuromodulatory functions associated with aFGF in the mammalian central nervous system.