Effect of repeated restraint stress and social isolation during preadolescence on number of center zone entries in an open field arena by adult <i>drd3</i>-EGFP mice.

<p>Adult male (<b>A</b> and <b>B</b>) and female (<b>C</b> and <b>D</b>) <i>drd3</i>-EGFP mice were either not stressed (blue, n = 11) or subjected to repeated restraint stress and social isolation during preadolescence (red, n = 11). Number of center zone entries were measured in an Open Field test in adulthood. Significant reduction in number of entries was observed in stressed male <i>drd3</i>-EGFP mice during the initial 20 minute period following the placement of the mice in the arena (*, p<0.05, two-way repeated measure ANOVA, post-hoc SNK test; <b>A</b>). The total number of center zone entries over the entire 60 minute observation period was also significantly reduced in stressed male <i>drd3</i>-EGFP mice (*, p<0.05, Student’s <i>t</i>-test). The stress-induced changes in locomotor activity was absent in adult female <i>drd3</i>-EGFP mice subjected to preadolescent stress and social isolation (<b>C</b> and <b>D</b>). Error bars represents ± SEM.