Prefrontal cognitive performance of healthy subjects positively correlates with 18F-FDOPA uptake in positron emission tomography

Dopaminergic transmission influences cognitive processes generally regarded as prefrontal functions. 18F-fluorodopamine (FDOPA) uptake in Parkinson’s disease and schizophrenia previously was found to correlate with cognition. The present FDOPA-PET study evaluates the influence of dopaminergic transmission and prefrontal performance under healthy conditions. Nine healthy volunteers underwent one single FDOPA positron emission tomography (PET). After intravenous bolus infusion of 137–263 (200,0±47) MBq a 120 min PET scan was performed. Arterial plasma samples were obtained simultaneously. The net blood-brain clearance of FDOPA (Kinapp) was calculated by volume-of-interest analysis and voxelwise using SPM. Additionally, Wisconsin-Card-Sorting-Test (WCST), Stroop-Test, Trail-Making-Test (TMT-A/B) and Continuous-Performance-Test (CPT-M) were performed. Positive correlations exist for ‘prefrontal’ performance in CPT (number of hits; sensitivity index), TMT-B and Stroop-interference with FDOPA-uptake in caudate nucleus, putamen and midbrain. Additionally, using SPM analysis Stroop interference correlated significantly in superior temporal gyrus. The data emphasize a strong and direct influence of striatal dopamine transmission on ‘prefrontal’ cognitive performance.