Figure 8.

Open field, elevated plus maze and startle findings from Experiment 4. In open field testing, yohimbine treatment (1 mg/kg, i.p.) suppressed rearing in the no psychosocial stress group (NS-YOH), an effect that was significantly exacerbated by prior stress experience (S-YOH) (top left). On the elevated plus maze, both psychosocial stress groups (S-YOH, S-VEH) spent significantly less time in the open arms than the no psychosocial stress groups (NS-YOH, NS-VEH) (top right). In addition, only the yohimbine-treated psychosocial stress group (S-YOH) exhibited significantly less motor activity on the elevated plus maze than the vehicle-treated no psychosocial stress group (NS-VEH) (bottom left). Psychosocial stress significantly increased startle responses to the 100 and 110 dB auditory stimuli (bottom right). *p < 0.01 versus all other groups; **p < 0.0001 versus the no psychosocial stress groups; ***p < 0.01 versus the vehicle-treated no psychosocial stress group; βp < 0.05 versus the respective no psychosocial stress groups. Data are group means ± SEM.