• A group of healthy control subjects and patients with Parkinson's disease were investigated
using positron emission tomography and two tracers as indicators of different specific
properties of the presynaptic dopaminergic system in caudate nucleus and putamen. The
first tracer, 6-l-(18 F)-fluorodopa, was used as an analog of levodopa to assess its regional
brain uptake, conversion into, and retention as dopamine and further metabolites. The
second tracer,(11 C)-nomifensine was employed as an indicator of striatal monaminergic …