SYNAPSE 14:128-131 (1993) In Vivo Imaging of Monoaminergic Nerve Terminals in Normal and MPTP-Lesioned Primate Brain Using Positron Emission Tomography (PET) and ["CITetrabenazine

ABSTRACT The first successful in vivo imaging of monoamine vesicular transport-ers in the living primate brain is described, using [llcltetrabenazine (["ClTBZ) and Positron Emission Tomography (PET). Radioligand uptake into brain is rapid, and at short time periods (10-30 minutes) the higher uptake and retention of the radiotracer in the more densely dopaminergic innervated striaturn is clearly visualized. Specific bind-ing in striatum can be entirely blocked with co-administration of a pharmacological dose (1 m a g i.v.1 of tetrabenazine. In a unilaterally MPTP-lesioned monkey, specific binding of radioligand was absent in the striatum on the lesioned side, with no effect on ra-diotracer distribution in the cortex, cerebellum or contralateral striatum. PET imaging with [llC]TBZ provides a new approach to the in vivo study of monoaminergic neurons and their loss in neurodegenerative diseases