Comparative anatomo-functional imaging of two neuroreceptors and glucose metabolism: a PET study performed in the living baboon.

Regional specialization of two types of neuroreceptor--opiate and dopamine--was mapped by positron emission tomography (PET) in the subcortical gray matter of the living baboon and analyzed in comparison with glucose metabolism. The three radiopharmaceuticals used--[18F]3-acetylcyclofoxy, [11C]3-N-methylspiperone, and [18F]2-fluoro-2-deoxyglucose--traced opiate- and dopamine-receptor distribution and regional glucose metabolism, respectively. A combination of high spatial resolution (6-7 mm) and the intrinsic sensitivity of the PET method made possible the detection of nanomolar concentrations of neuroreceptors and micromolar concentrations of metabolized glucose, with different and distinctive anatomo-functional distributions in thalami and basal ganglia.