Asymptomatic striatal dopamine depletion: PET scans in unilateral MPTP monkeys.

In cynomolgus monkeys, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) produces irreversible clinical, chemical, and pathological alterations that are similar to those found in Parkinson's disease. Unilateral carotid injections of this toxin produce ipsilateral nigrostriatal dopamine depletion while sparing the contralateral dopaminergic pathways. In order to study the damage to the nigrostriatal dopamine system in asymptomatic animals after unilateral MPTP administration, positron emission tomography (PET) scans were performed with [18F]fluoro-L-dopa (6-FD). This study demonstrates that clinically asymptomatic MPTP lesions may be assessed in vivo using 6-FD and PET.