When you walk into a room, how do you know where you're going once you've learned your way around? And how do you remember that when you enter the room again?
Three scientists, who recently won the Nobel Prize for medicine, asked that question, and figured out the results of how our brain navigates spaces and stores maps for later use.
Think of this functioning of our brains as a sort of Google Maps. When you enter a space, your brain takes in your surroundings and as you walk around that space, it stores maps with details of how to get from point A to point B, so that the next time you enter that space, you immediately know where you're going and you don't have to think about it.
There's a whole process that happens in the brain to make that happen, and scientists John O'Keefe, May-Britt Moser and Edvard Moser have figured it out.
Although scientists have wondered for a long time what makes this happen, O'Keefe discovered the first part of the brain's positioning functions in 1971 by discovering specific nerve cells, called "place cells," in the brain's hippocampus. This discovery came after observing rats, which showed that this nerve cell activated when he placed the rodent in a specific part of a room. Other similar nerve cells responded the same way in other parts of the room.
However, it wasn't until 2005, that the Mosers discovered the rest of the brain's inner positioning system. Following up on O'Keefe's work, they mapped connections in the hippocampus of rats as the rodents moved through a room. After looking at the brain activities of the rats, they discovered nerve cell activity in the brain's entorhinal cortex. Those nerve cells, though, activated in a grid-like pattern, marking coordinates in the brain as the rats moved through the room. These "grid cells," combined with place cells, allows the brain to position itself and navigate spaces with ease.
"The discoveries of John O´Keefe, May-Britt Moser and Edvard Moser 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?" writes the Nobel Foundation.
This discovery could prove important in the field of Alzheimer's research. Patients diagnosed with the disease frequently have problems with recognizing and navigating spaces, even familiar ones. Learning about how this process works in a healthy brain could help treat the loss of these nerve cells in a brain with Alzheimer's.
Although O'Keefe's work was originally dismissed, the Moser's work verified and built upon his initial discovery. And now, together, the three have won the Nobel Prize.
"This is great news and well deserved," says John Stein, a physiology professor at Oxford. "I remember how great was the scoffing in the early 1970s when John first described 'place cells'...Now, like so many ideas that were at first highly controversial, people say: 'Well that's obvious!'"
