In 1958, Arvid Carlsson discovered that levodopa (L-Dopa) was effective in treating the symptoms of Parkinsonism. a treatment still widely used today. Levodopa is the precursor to dopamine. Clinicians use levodopa as a dopamine replacement agent for the treatment of Parkinson disease.

In 2000, The Nobel Prize in Physiology or Medicine was awarded jointly to Carlsson, Paul Greengard and Eric R. Kandel “for their discoveries concerning signal transduction in the nervous system.”