ROBERT SIEGEL, HOST:
The Nobel Prize in physiology or medicine was announced today. The 1.1 million-dollar prize will be split between John O'Keefe of University College London and a husband-and-wife team, May-Britt and Edvard Moser of the Norwegian University in Trondheim. NPR's Rob Stein explains why they won.
ROB STEIN, BYLINE: The three neuroscientists won for discovering what the Nobel committee calls our inner GPS.
(SOUNDBITE OF ARCHIVED RECORDING)
OLE KIEHN: An inner GPS that makes it possible to know where we are and find our way.
STEIN: That's Ole Kiehn, a professor of neuroscience who helped pick the winners.
(SOUNDBITE OF ARCHIVED RECORDING)
KIEHN: The abilities to know where we are and find our way are essential to our existence.
STEIN: How our brains do this has fascinated and puzzled philosophers and scientists for hundreds of years. Then John O'Keefe made a crucial discovery in 1971. He measured the activity of cells in a part of the brain called the hippocampus as rats moved around the room.
(SOUNDBITE OF ARCHIVED RECORDING)
KIEHN: And much to his surprise, he found in hippocampus nerve cells that were only active when a rat was in a certain position in the environment.
STEIN: And when the rats were in a different place, different cells became active. He called these place cells.
(SOUNDBITE OF ARCHIVED RECORDING)
KIEHN: The place cells in hippocampus generate many inner maps of the environment which gives us information about where we are and how we can recognize new environments.
STEIN: More than three decades later, the Mosers discovered another part of the brain's GPS system while studying connections between nerve cells.
(SOUNDBITE OF ARCHIVED RECORDING)
KIEHN: They discovered a complete new type of nerve cell activity.
STEIN: Nerve cell activity by cells they called grid cells because they create a kind of mental grid in the brain.
(SOUNDBITE OF ARCHIVED RECORDING)
KIEHN: Activity in many grid cells provide the brain with a coordinate system that allows to keep track on how far we are from a starting point and the turning point.
STEIN: And that's how we're able to figure out how to plan routes to get from one place to another. The committee says the discoveries have led to fundamental insights into how the brain produces all kinds of complicated thinking powers like memory and planning.
(SOUNDBITE OF ARCHIVED RECORDING)
KIEHN: The discoveries by the Nobel laureates provided a paradigm shift in our understanding of how groups of specialized nerve cells work together to execute our brain functions.
STEIN: The Nobel committee noted that one of the early signs of Alzheimer's disease is that people start getting lost and can't find their way home. So someday, this research might lead to ways to help people suffering from this devastating brain disease. May-Britt Moser described her reaction when she got a phone call from the Nobel committee.
MAY-BRITT MOSER: He said, you won the Nobel Prize. And I started to cry, and I said don't joke with me. (Laughter). I don't believe it. I think I'm dreaming. (Laughter).
STEIN: Rob Stein, NPR News. Transcript provided by NPR, Copyright NPR.
