Ultrastructural localization of fibroblast growth factor in neurons of rat brain.

The distribution of fibroblast growth factor (FGF) at the ultrastructural level in the brain of young (15- and 20-day-old) and adult (3-month-old) rats was investigated by immunocytochemistry. Strong staining was observed in most neurons of the cortex of young rat brain. In the same brain area of adult rat many neurons were also stained intensely, while others were negative. Neurons in the other parts of the brain and especially in the adult rat, were generally more weakly stained. The reaction product was located in the cytoplasm of the neuronal cell bodies and their processes. Astrocytes, oligodendrocytes, microglial cells, meningeal cells, choroïd epithelial cells, ependymal cells and capillary endothelial cells showed no staining.