Figure 5.
Progression of locomotor performance attributable to administration and withdrawal of quipazine during continued robotic training. After the initial period of robotic training, which ended at P79, the number of steps (A) and the step shape consistency (B) of the mice continued to improve when robotic training and quipazine treatment were used together (P91) and then decreased when quipazine was withdrawn (P105a). This suggests that the improved performance observed after the combination treatment was primarily mediated by quipazine and, hence, that the net performance was attributable to an interaction effect between quipazine and robotic training. Moreover, an additional bolus treatment with quipazine (P105b) immediately generated stepping that was significantly better than that exhibited at P91, despite the fact that quipazine had not been administered during the preceding 9 d. This finding suggests that the acute quipazine treatment improved stepping by facilitating effects of chronic robotic training that were masked in the absence of drug treatment. Unlike the number of steps and step shape consistency, the step rhythm (C) improved steadily throughout the course of robotic training, as depicted by the plot of inverse FFT score. This is consistent with the results of experiments II and III, which indicated that robotic training has a greater effect on step rhythm than quipazine. RT, Robotically trained; +Q, treated with quipazine; -Q, not treated with quipazine.