Fig 4. Effect of repeated restraint stress and social isolation during preadolescence on number of center zone entries in an open field arena 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). Number of center zone entries were measured in an Open Field test in adulthood. Significant increase in number of entries was observed in stressed male drd3-null mice during the initial 10 minute period following the placement of the mice in the arena (*, p<0.05, two-way repeated measure ANOVA, post-hoc SNK test; A). The total number of center zone entries over the entire 60 minute observation period was also significantly increase 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.