Fig. 4

Assessment of open field test. All indexes were recorded in a test of 5 min. All data were represented as the mean ± SEM (n = 11), * refers to p < 0.05, *** refers to p < 0.000 vs. CSD group. The time spent in center of CON group was significantly shorter compared with CSD group, and CEO decreased the central time (a). The total distance travelled (b), number of crossing squares (c), max continuous distance (d), mean velocity (e) of CON group all decreased significantly compared with CSD group respectively, and treatment of CEO showed a reduction trend on these parameters. Number and time recorded of vertical activity (f, g) showed the same situation as horizontal activity. No significant difference was found in the number of grooming behavior (h). The time of grooming (i) in CON group were significantly higher than CSD group. Number of defecations (j) of CSD group increased significantly compared with CON group, and CEO was seen to decrease the measure significantly