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“An odd combination” is how neuroscientists describe the joint winners of
this year’s Nobel Prize in Physiology or Medicine. Arvid Carlsson, Paul
Greengard and Eric Kandel are all recognised for providing pivotal advances in
our understanding of how the brain works—and are rewarded with their share
of the £625,000 payout. “I wouldn’t have bracketed those three together,”
says Philip Strange of Reading University. “But they are three great men.”

In the 1950s, Carlsson, from Gothenburg University in Sweden, showed that a
brain chemical called dopamine is important for controlling movement. This led
to the discovery that Parkinson’s disease occurs when dopamine-producing nerve
cells in the brain die. As a result the dopamine precursor, L-dopa, was
developed as a successful drug for the disease. “Carlsson’s discovery has had a
massive effect on the lives of hundreds of thousands of people with Parkinson’s
disease,” says pharmacologist Peter Jenner of King’s College London. “It was
absolutely fundamental. He should have been given the Nobel Prize years ago.”
His work ultimately led to the development of modern antidepressant drugs such
as Prozac.

Carlsson, at 77, says he is surprised but happy about receiving the prize
after so long. “I feel great!” he says.

Paul Greengard from Rockefeller University in New York discovered how
dopamine and similar neurotransmitters work. He showed that they modify proteins
at synapses—the points of contact between nerve cells—in a process
called “phosphorylation”. Altering these proteins controls how excitable the
nerve cells are. “This was pioneering work,” says Steve Nahorski of Leicester
University. “But now we know how important his work was. Now we believe that all
synapses are controlled by phosphorylation.”

Eric Kandel of Columbia University in New York studied what happens to
synapses by studying sea slugs. His research showed for the first time that
learning can be explained simply by nerve cell activity. When you prod a sea
slug, it quickly retracts from the stimulus. But keep prodding it and it stops
responding. In this way, Kandel showed that continued phosphorylation of
proteins at the synapses governs their ability to carry signals. “He has made a
fantastic contribution to neuroscience,” says neuroscientist Seth Grant of
Edinburgh University, who worked with Kandel in the 1990s.

However, Grant suggests that another scientist, Tim Bliss of the National
Institute of Medical Research in London, might consider himself a little unlucky
not to have a share of the prize. It was Bliss who showed that the same
mechanisms accompany learning in mammals. Bliss, however, praises the choice of
Kandel. “His work set the landscape for research in the field,” he says. But
might they have rewarded him too? “They might have done, but they didn’t,” he
says.