The fibroblast growth factor system is downregulated following social defeat

The fibroblast growth factor (FGF) system has previously been found to be altered in post-mortem brains of individuals with major depressive disorder (MDD). The present study tested whether the FGF system is altered following acute social defeat. Rats were exposed to four consecutive days of either a social defeat paradigm or novel cages. Animals were sacrificed after the last social defeat session and gene expression was assessed in the hippocampus by mRNA in situ hybridization. Molecular components of the FGF system were significantly downregulated following social defeat. Specifically, FGF2 and FGFR1 mRNA expression was decreased in various subfields of the hippocampus. Decreased tone of the FGF system following an acute social stressor is congruent with human post-mortem results of FGF system downregulation in depression. These findings suggest that modulating the FGF system may have therapeutic value in the treatment of MDD.