Fig 3. Effect of repeated restraint stress and social isolation during preadolescence on locomotor activity in an open field arena test by adult drd3-null mice.

Adult male (A and B) and female (C and D) drd3-null mice were either not stressed (blue, n = 5) or subjected to repeated restraint stress and social isolation during preadolescence (red, n = 5). Horizontal locomotor activity were measured in an Open Field test in adulthood. Compared to non-stressed drd3-null male mice, preadolescent stressed male drd3-null mice exhibited significant increase in locomotor activity (A) only during the initial 15 minute period following the placement of the mice in the arena (*, p<0.05, two-way repeated measure ANOVA, post-hoc SNK test). The total locomotor activity over the entire 60 minute observation period was not significantly altered in stressed male drd3-null mice (p>0.05, Student’s t-test). The stress-induced changes in locomotor activity was absent in adult female drd3-null mice subjected to preadolescent stress and social isolation (C and D). Error bars represents ± SEM.