Fig. 2

Effects of GPS on the number of marbles buried in the marble burying test in mice. Mice (ICR, male, 25–30 g) were orally treated with GPS (30, 50, 100, 200 and 400 mg/kg), GP-WX (50 mg/kg), GP-EX (50 mg/kg, positive control) or saline (0.9 %) once a day for 10 days. Mice were also exposed to EF stimuli (intensity, 0.6 mA, 1 s every 5 s, periods, 3 min) for chronic stress for 10 days (chronic EF-stressed groups, Stress). The marble burying test was performed as described under the Methods section. The results are expressed as means ± S.E.M. for 8–10 animals per group. **p < 0.01 compared with control group; ^#p < 0.05, ^##p < 0.01 compared with chronic EF-stressed group (one-way ANOVA followed by Tukey’s test); ^§p < 0.05 compared with between the un-stressed groups and stressed groups (two-way ANOVA followed by Tukey’s test)