Explicit motor memory activates the striatal dopamine system.

We studied the pattern of striatal dopamine release during performance of an explicit motor memory task in healthy volunteers. The release was estimated by dynamically measuring concentration of a dopamine ligand using a positron emission tomography camera. An increased release of endogenous dopamine in the dorsomedial aspect of posterior putamen and in the anterior part of the caudate bilaterally was observed, during task performance. As we have earlier observed dopamine release in all of these areas, except the right putamen, in an implicit motor memory task, it seems that the striatal dopaminergic network for implicit and explicit motor memories are essentially similar.