Fig. 6

Existence of stress after short-term immobilization. a Corticosterone serum levels. b Forced swim test. c Sucrose consumption. d Body weight. Post-surgical exposure to short-term immobilization significantly elevated the level of corticosterone in serum (a), increased immobility time in a forced swim test (b), and decreased sucrose consumption in a sucrose preference test (c) in both the sham incision plus immobilization (S + Im) group and the incision plus immobilization (In + Im) group compared to the sham plus control (S + C) group. These changes were not observed in the incision plus control group (a–c). No significant differences in changes in body weight between before surgery and on day 9 post-surgery were seen among the four groups (d). Mean ± SEM. **P < 0.01 vs the corresponding sham plus control group. N = 5/group. C control, Im 3d immobilization, In incision, S sham incision