Methylphenidate improves cue navigation in the Morris water maze in rats

Despite its still rapidly increasing use in the treatment of the attention deficit/hyperactivity disorder, the effects of methylphenidate on behavior and learning are not yet fully understood. We have used the Morris water maze to study effects of methylphenidate (1 mg/kg) on target-oriented behavior and visuospatial learning in young rats. Although the relatively low dose of 1 mg/kg methylphenidate changed the behavior in the Morris water maze when the goal was visible, reducing times to reach the visible platform, learning of the position of the hidden platform, was not influenced, nor was 'relearning' after shifting the position of the platform. These results indicate that methylphenidate can influence goal-oriented behavior at doses that do not change visuospatial learning.