Locomotor learning is impaired in DA-βcat KO mice. Time spent on the rod of the accelerating rotarod for each trial completed on days 1, 2, 3, and 10. Learning retention between days of training was analyzed by pooling the average values for the last trial on each day and the first trial of the following training day. Values represent the average mean latency to fall expressed in sec ± SEM. Two-way ANOVA; (*) P < 0.05, (**) P < 0.01, (***) P < 0.001.