Xiao, HS (reprint author), Chinese Acad Sci, Shanghai Inst Biol Sci, Inst Neurosci, Lab Sensory Syst, 320 Yue Yang Rd, Shanghai 200031, Peoples R China,
Using cDNA array, we observed the expression of eight members of the fibroblast growth factor (FGF) family, FGF 2, 5, 7,9,10,13 and 14, in rat lumbar 4 and 5 dorsal root ganglia (DRGs). Over a period of 28 days after sciatic nerve transection, the array signals for FGF 2 and 7 were significantly increased in the DRGs, while FGF 13 decreased. Using the reverse transcription polymerase chain reaction (RT-PCR), we confirmed the axotomy-induced changes in the expression of FGF 7 and 13. In situ hybridization showed that FGF 13 was expressed in 60% of DRG neurons under normal circumstance. Seven days after axotomy the number of FGF 13-positive neurons was decreased to 18%, but partially recovered to 40% after 28 days. FGF 13 immunoreactivity was also decreased. These data indicate that FGFs are important for DRG neurons under normal circumstance and after nerve injury.