The potential of dopaminergic treatments to improve upper limb motor moveme
nts was tested in 7 aged rhesus monkeys using L-3,4-dihydroxyphenylalanine
(L-dopa) or the selective dopamine uptake inhibitor 1-2(bis[4-fluorophenyl]
methoxy) ethyl)-4-(3-phenylpropyl) piperazine hydrochloride (GBR-12909). S
ix young monkeys were studied for comparison. L-Dopa or GBR-12909 improved
upper limb motor performance by up to 40% in the aged animals. At this poin
t their performance was comparable to that of young adults. Dopaminergic th
erapy could be useful in elderly humans experiencing declines in upper limb
motor functions.