A new device for the quantitative assessment of dopaminergic drug effects in unilateral MPTP-lesioned monkeys

Non-human primates exposed to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) have been employed to study the clinical features of parkinsonism. Monkeys lesioned by unilateral intracarotid administration of MPTP display spontaneous and drug responsive turning behavior. However this seems to correlate poorly with their clinical deficits. We describe an objective measurement of arm movement velocity, applied in 4 cynomolgus monkeys before and after unilateral administration of MPTP. Reduced movement velocities correlated with clinical signs of unilateral flexed arm posture, rigidity, tremor and bradykinesia and could be reversed with L-DOPA therapy. This measurement technique has advantages for the quantitative assessment of parkinsonian deficits and will permit the evaluation of dopaminergic therapy and transplantation in non-human primates.