Fig. 4

Representative photographs illustrating the effects of GPS on c-Fos-immunoreactive cells in the PVN (a) and the number of c-Fos-immunoreactive cells in the PVN (b). 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. GPS (100 mg/kg) was shown as a representative of the un-stressed groups. a Immunoblots of lysates from the brain were probed with c-Fos antibodies, and the total c-Fos-immunoreactive cells were measured as described under the Methods section. The arrow indicates nucleus of c-Fos-positive neurons. Scale bar is 100 μm. b The number of c-Fos-immunoreactive cells was counted in the PVN and was expressed as a percentage of the control groups. The number of c-Fos-immunoreactive cells of the control groups was 24 ± 4 cells per section. The results are expressed as means ± S.E.M. for 8 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)