SHAFAQNA- A British-American and two Norwegian scientists were awarded this year’s Nobel Prize in Physiology or Medicine for discovering brain circuits that forms an “inner GPS” system that allows us to navigate our environment.
Half the prize was awarded to American-born John O’Keefe for discovering nerve cells that get activated in different combinations to enable the creation of a spatial map that determines our sense of “place.”
The other half was shared by a Norwegian couple, May-Britt Moser and Edvard I. Moser, who discovered other nerve cells that also enable precise positioning and pathfinding.
Taken together, the discoveries “have solved a problem that has occupied philosophers and scientists for centuries—how does the brain create a map of the space surrounding us and how can we navigate our way through a complex environment,” the Nobel Assembly, the body that makes the final decision on the winners, said in a statement.
The research has paved the way for a better understanding of other cognitive processes, including memory, thinking and planning. And it may one day provide medical benefits.
For example, patients with Alzheimer’s disease often lose their way and cannot recognize where they are. Knowledge of how the brain’s inner global positioning system works could shed light on how spatial memory loss occurs.
Dr. O’Keefe, who is a dual U.K.-U.S. citizen, is director of the Sainsbury Wellcome Centre in Neural Circuits and Behavior at University College London. Ms. Moser is the director of the Centre for Neural Computation in Trondheim, Norway. Mr. Moser is the director of the Kavli Institute for Systems Neuroscience in Trondheim.
By watching rats navigate labyrinths, scientists had long suspected that the animals likely had cognitive circuitry that allowed them to find their way. But it was far from clear how any such map would be represented in the brain.
In 1971, Dr. O’Keefe found a key part of the answer. By connecting electrodes to the brains of rats as they moved freely in a room, he discovered that certain nerve cells got activated when the animal was in a particular location. Crucially, the cells weren’t just registering the location but they were also forming circuits that constituted an inner map of the location.
If the rat was placed in another part of the room, another set of nerve cells got activated. When the animal was moved back to the original location, the original cells were reactivated. The upshot: the memory of a place was stored as a specific combination of these nerve or “place” cells. These “place” cells, Dr. O’Keefe found, are located in a part of the brain called the hippocampus.
In 2005, while conducting similar experiments on rats, the husband-and-wife team of May-Britt Moser and Edvard I. Moser found that nerve cells in a nearby part of the brain called the entorhinal cortex got activated when the animals passed certain locations. Together, the grid cells are a type of navigation chart—a system of coordinates that allow the animals to navigate spatially.
By studying patients undergoing brain surgery, researchers have evidence that similar “place” and “grid” cells also exist in humans.
“Before the discovery of ‘place cells’ we didn’t have any sense of how the brain built maps and computed this information on a cellular level and the understanding of these ‘grid-like cells’ really gives us a navigational chart to operate on as well,” said Juleen Zierath, professor of clinical integrative physiology and chairman of the Nobel committee, in an interview.
These discoveries, though, form just a small part of the complex workings of the human brain. Scientists are now trying to learn more. The U.S. government recently embarked on a large-scale project to create the most comprehensive map of the human brain assembled so far. Europe also has a large $1-billion brain science project in the works.
Regarded as the most prestigious prize for medical and physiological research, the 8 million Swedish kronor ($1.1 million) Nobel award is given to recipients whose discoveries greatly enhance the understanding of life or the practice of medicine. The decision is made by the Nobel Assembly at Stockholm’s Karolinska Institute—a group of 50 professors whose 18-member working body evaluates nominations from scientists around the world and proposes top candidates.