FIG. 4.

Mean (±SEM) percentage of time spent in the target quadrant (i.e., where the platform was previously located) after single-probe trials on treatment day 19 and nontreatment days 49 and 109 after controlled cortical impact or sham injury. The TBI+BRO and SHAM groups displayed significant memory retention on all 3 test days, compared to the TBI+HAL, TBI+RISP, and TBI+VEH groups, as evidenced by higher percentages of the 30-sec allotted time spent in the target quadrant. There were no significant differences among the TBI+HAL, TBI+RISP, and TBI+VEH groups at any time point. The dashed line represents performance at the chance level (25%). *p<0.005 versus all TBI groups at each time point; **p<0.0001 versus TBI+VEH, TBI+HAL, and TBI+RISP groups at each time point. No other group comparisons were significant. TBI, traumatic brain injury; VEH, vehicle; HAL, haloperidol; RISP, risperidone; BRO, bromocriptine.