Figure 4.

Mean (+SEM) behavioral responses at baseline (plain bars) and following 15 minutes of immobilization stress (hashed bars) as measured by distance traveled (A, C) and center time (B, D) in the open field during the week following the CPP reinstatement test. Activity was assessed during the first 5 minutes (A, B) and entire 30 minute (C, D) test. (A) For the first 5 minute data, there was no significant difference in distance traveled from baseline to stress testing for either treatment group. (B) During the first 5 minutes, sedentary exhibited a trend of rats spending more time in the center following stress compared to baseline, and the opposite trend was seen in exercise rats. Neither of these trends, however, reached significance. (C) For the entire 30 minute session data, there were no differences between baseline and stress-induced activity for either group. (D) For the entire 30 minute session data, there was still a trend of sedentary rats spending more time in the center of the arena following stress compared to baseline, while there was no difference between baseline and stress in exercise rats.