Tremor and Involuntary Movements in Monkeys: Effect of L-Dopa and of a Dopamine Receptor Stimulating Agent

Either L-dopa, in combination with 1-alpha-methyldopa hydrazine (MK-486), or 1-(2''-pyrimidyl)-4-piperonylpiperazine, an agent that stimulates dopamine receptors, relieves surgically induced tremor in monkeys and concomitantly evokes involuntary movements. These results indicate that tremor and involuntary movements are associated with a common mechanism and that the activity of the dopamine receptors is involved in the regulation of these dysfunctions.