VISUALIZATION OF EXTRASTRIATAL DOPAMINE D(2)-RECEPTORS IN THE HUMAN BRAIN

[I-123]Epidepride, a potent and selective dopamine D2 radioligand, was administered to a 27 year old normal male volunteer. Single photon tomography revealed that peak striatal uptake occurred at 4 h after injection with a striatal : cerebellar ration of 7.8 rising to over 100 at 18 h post injection. Uptake above the levels seen in cerebellum was also noted in the thalamus, pituitary. hypothalamus and temporal lobe, particularly medially. Single photon tomography with [I-123] epicepride allows visulization of extrastriatal dopamine D2 receptors in man.