Fig. 1. Repeated restrant stress induced anxiety-like behaviors, whereas passive exercise counteracted stress-induced anxiety-like phenotypes. (A) Experimental design for treatment with 2 h×14 d RST (RST) and post-stress treatment with wheel-running exercise (RST+EXE) or imipramine (RST+IMI). Wheel-running exercise was treated for 1 h daily from post-stress days 1~21. Imipramine (20 mg/kg/day) was intraperitoneally (i.p) injected from post-stress days 1~21. Controls were aged-matched untreated naïve mice (CON). p1- p24 represent post-stress days. (B~D) The number of entries and time spent in the open arms in the elevated plus maze test (EPM) among mice treated with 2 h×14 d RST (RST), mice treated with 2 h×14 d RST followed by exercise (RST+EXE), mice treated with 2 h×14 d RST followed by imipramine (RST+IMI), and their control mice (CON). (E, F) Times spent in the dark box and latency to first exit from the light box in the light-dark box test (LDB) among mice treated with 2 h×14 d RST (RST), mice treated with 2 h×14 d RST followed by exercise (RST+EXE), mice treated with 2 h×14 d RST followed by imipramine (RST+IMI), and their control mice (CON). (G, H) Time spent in the center area and the total distance traveled in the open field test (OFT) among mice treated with 2 h×14 d RST (RST), mice treated with 2 h×14 d RST followed by exercise (RST+EXE), mice treated with 2 h×14 d RST followed by imipramine (RST+IMI), and their control mice (CON). (I, J) Latency to eating a food pellet placed at the center of the open field and the amount of food consumed after the latency analysis in the novelty-suppressed feeding test (NSF) among mice treated with 2 h×14 d RST (RST), mice treated with 2 h×14 d RST followed by exercise (RST+EXE), mice treated with 2 h×14 d RST followed by imipramine (RST+IMI), and their control mice (CON). (K) The number of marbles buried in the marble-burying test (MBT) among mice treated with 2 h×14 d RST (RST), mice treated with 2 h×14 d RST followed by exercise (RST+EXE), mice treated with 2 h×14 d RST followed by imipramine (RST+IMI), and their control mice (CON). (L~N) The U-shaped field in the context without (for habituation test; left panel) or with (for sociability test; right panel) a social target (L). Times spent in the right and left sides of the empty U-shaped field (habituation test; M) and social interaction levels (N) in the sociability test among mice treated with 2 h×14 d RST (RST), mice treated with 2 h×14 d RST followed by exercise (RST+EXE), mice treated with 2 h×14 d RST followed by imipramine (RST+IMI), and their control mice (CON). Data are presented as mean±SEM (n=7~16). * and **, p<0.05 and p<0.01, respectively, for the differences between the control and indicated groups (one-way ANOVA and Newman-Keuls post hoc test).
© Exp Neurobiol
