FIGURE 4.

Systemic CO gas administration exerted rapid antidepressant- and anxiolytic-like activities in mice. (A) After a 3-day-adaptation, each mouse was treated with saline (0.3 ml, i.p.) or CO gas (0.1, 0.3 ml, i.p.) daily 30 min prior to behavioral test. Time spent in central zone (B) and total distance traveled (C) had no effects when treated with CO gas in the OFT. In the NSF test, latency to feeding decreased (D) but not total food intake (E). No alteration occurred in sucrose preference (F) and in total intake (G) between three groups in the SPT. CO gas treatment decreased floating time (H) and immobility time (J), but not floating latency (I) in the FST and the immobility latency (K) in the TST. The data are expressed as mean ± SEM and were analyzed with separate one-way ANOVAs. *p < 0.05, **p < 0.01, ***p < 0.001 as compared to the saline-treated group. OFT, open field test; NSF, novelty-suppressed feeding; SPT, sucrose preference test; FST, forced swimming test; TST, tail suspension test (n = 8–9 per group).