FIGURE 1.

Dorsal hippocampal HO-1 overexpression produced antidepressant-like effects. (A) AAV-HO-1 virus was infused bilaterally into the dorsal hippocampus of mice before behavioral testing. (B) HO-1 protein levels were significantly increased in the dorsal hippocampus area, as imitated by immunofluorescence staining (i) and Western blot (ii). Time spent in the central zone (C) and total distance (D) were similar across all groups in the OFT. HO-1 overexpression has no effect on latency to feeding (E) and total food intake (F) in the NSF test. No change occurred in sucrose preference (G) and total intake (H) after administration of AAV-HO-1 in the SPT. HO-1 overexpression significantly decreased the floating time (I) in the FST and immobility time (K) but not floating latency (J) and immobility latency in the TST (L). Dorsal hippocampal AAV-GFP infusion had no effects on these behaviors. The data are expressed as mean ± SEM and were analyzed with separate one-way ANOVAs. **p < 0.01, ***p < 0.001 versus naive group. NAV, naive; AAV, adeno-associated virus; HO-1, heme oxygenase-1; OFT, open field test; NSF, novelty-suppressed feeding; SPT, sucrose preference test; FST, forced swimming test; TST, tail suspension test (n = 4 per group for WB analysis, n = 7–9 per group for behavioral tests).