FIGURE 6.

Mice show a preferred location for stereotypy across continuous treatment. (a) Example of stationary vs. circling behavior of a single mouse on D-amphetamine treatment days 1, 7 and 21 and on challenge day. An angular coordinate deflection from −180° to +180° (vertical lines) represents a full revolution around the cage. (b) For each mouse, the coordinate position data, either before (pre) or after (post) drug injection was plotted against the average coordinate position during that time interval across all days and the average correlations were plotted. Beginning on the second day of drug treatment, there was a high correlation across days for the post-injection period, reflecting a relatively constant favored location. The correlation for the pre-injection period was low, indicating that the mice did not have a highly preferred location before drug injection. Averages and +SEM across mice are shown (n = 12 mice).