Figure 3.

Adult fibroblast growth factor 2 (FGF2) administration rescues the anxiety phenotype. (A) Timeline of FGF2 rescue experiment. (B, C) Fgf2 knockout (FGF2 KO) mice show increased anxiety on the elevated plus maze (B) and the open field (5 minutes) (C), and FGF2 ligand administration returns anxiety behavior to that observed in wild-type (WT) mice. No differences were observed on the forced swim task between genotypes; however, a small antidepressant effect of FGF2 was observed in WT mice (D) (WT, vehicle [Veh], n = 8; Fgf2 KO, Veh, n = 8; WT, FGF2, n = 10; Fgf2 KO, FGF2, n = 8). (E) FGF2 administration restored the increased basal corticosterone level to that of WT mice (WT, Veh, n = 4; Fgf2 KO, Veh, n = 4; WT, FGF2, n = 3; Fgf2 KO, FGF2, n = 3). (F) FGF2 administration restored decreased hippocampal glucocorticoid receptor (GR) messenger RNA (mRNA) found in Fgf2 KO mice to levels observed in WT mice. (G) Fgf2 KO mice showed a significant increase in amygdalar GR mRNA, regardless of FGF2 administration (WT, Veh, n = 4; Fgf2 KO, Veh, n = 4; WT, FGF2, n = 3; Fgf2 KO, FGF2, n = 3). (H) Fgf2 KO also showed an increase in GR protein in both the cornu ammonis and dentate gyrus regions of the hippocampus (WT, Veh, n = 4; Fgf2 KO, Veh, n = 4; WT, FGF2, n = 4; Fgf2 KO, FGF2, n = 4). Asterisks denote significant differences from all other groups, p < .05. Lines indicate significant differences between two groups, p < .05. Error bars denote SEM. Cort, corticosterone; DAPI, 4′,6-diamidino-2-phenylindole dihydrochloride.