Not So Dopey Dopamine

The neurotransmitter dopamine ranks among the most powerful of the brain's master molecules. A regulator of mood and movement, it plays a principal role in Parkinson's disease, drug addiction and schizophrenia. For years after its discovery in 1910, however, scientists considered dopamine merely a stepping-stone to the more powerful compound noradrenaline.

But as the Nobel Prize committee reminded the world last week, that view radically changed in the late 1950s when Swedish pharmacologist Arvid Carlsson brought dopamine out of the shadows. First Carlsson established that the areas of the brain known as the basal ganglia contained very high levels of dopamine. Then he administered a drug that lowered those concentrations in laboratory mice. Soon the mice began to stagger and reel, losing control of their voluntary movements.

Carlsson's mice, in other words, resembled human patients with Parkinson's disease--and L-dopa, the dopamine-boosting compound he used to restore normality to the mice, soon emerged as the frontline treatment for Parkinson's.

That discovery alone merited a Nobel Prize, but Carlsson soon made another. For years, doctors prescribed drugs for schizophrenia with a kind of blind chemical faith; the medications reduced symptoms, but no one knew just how. In the 1960s, Carlsson discovered that they work by preventing nerve cells from taking up dopamine. That penetrating insight led directly to better antischizophrenia drugs.

Last week Carlsson, 77, a professor emeritus at Sweden's University of Gothenburg, finally won a Nobel. Sharing the prize for Physiology or Medicine with him were Columbia University's Eric Kandel, 70, who laid bare the molecular foundations of learning and memory, and Rockefeller University's Paul Greengard, 74, who elucidated the chemical cascade touched off by dopamine and other neurotransmitters. In each case, the Nobel was surely long overdue and richly deserved.