Fig. 1: Modafinil reverses depressive-like behaviors but has no effects on the reduction of uterus weight and estradiol concentration in ovariectomized mice.

a Behavioral tests were conducted during the modafinil (MOD) administration. On the day after the last MOD injection, the uterus of each mouse was separated and weighed. b The uterus coefficient was calculated as ratio of the uterine weight and body weight of each mouse at the end of the experimental sequences after 13-day MOD administration. n = 14 per group. c The concentration of estradiol in serum determined by enzyme-linked immunosorbent assay in each group. Sham+Vehicle (Veh): n = 9; OVX+Veh: n = 7; OVX+MOD 45 mg/kg: n = 5. d, e Percentage of immobility time in the TST (d) and FST (e) carried out at 11 days and 12 days, respectively, after MOD injections. Sham+Veh, OVX+MOD 45 mg/kg: n = 14 per group, OVX+Veh: n = 13, OVX+MOD 11.25 mg/kg: n = 8. *p < 0.05, **p < 0.01 compared with the Sham+Veh group; ^#p < 0.05, ^##p < 0.01 compared with OVX+Veh group in (b–e). f Time-course changes of the locomotion activity after 10 days of MOD treatment. **p < 0.01 OVX+Veh group compared with the Sham+Veh group; horizontal pink bars under the curve indicate statistical differences (p < 0.05) of the OVX+MOD group versus Sham+Veh group; ^##p < 0.01 OVX+MOD group compared with OVX+Veh group. Sham+Veh, OVX+MOD 45 mg/kg: n = 15 per group, OVX+Veh: n = 13. The horizontal filled and open bars on the x-axes indicate the 12-h active phase and 12-h inactive phase, respectively. EPT elevated plus-maze test, OFT open field test, LAR locomotor activity recording, TST tail suspension test, FST forced swimming test.