For centuries, the mysteries of grey matter have baffled scientists and researchers alike. How can humans manage to store countless moments, past and present, in one single organ? How can animals map their path back and forth? How do we figure out a shortcut to work when there's a big traffic jam? How do we recall where we parked our car? So on and so forth.
The brain, as it turns out, has a GPS-like function that enables people to produce mental maps and navigate the world — a discovery for which husband-and-wife scientists Edvard Moser and May-Britt Moser of Norway, and New York-born researcher John O'Keefe were recently honored for breakthroughs in experiments on rats that could help pave the way for a better understanding of human diseases such as Alzheimer's. This solves the problem of how the brain creates a map of the space surrounding us and how we navigate our way through a complex environment. In other words, it reveals brain's internal positioning system and gives clues to how strokes and Alzheimer's affect the brain.
"We can actually begin to investigate what goes wrong" in Alzheimer's, said O'Keefe. "The findings might also help scientists design tests that can pick up the very earliest signs of the mind-robbing disease, whose victims lose their spatial memory and get easily lost," he added.
It was in London in 1971 where O'Keefe, conducting his research on rats, discovered the first component of the brain's positioning system. O'Keefe, now director at the center in neural circuits and behavior at University College London, found that a type of nerve cell in a brain region called the hippocampus was always activated when a rat was in a certain place in a room. Other nerve cells were activated when the rat was in other positions. O'Keefe, thereafter, concluded that these "place cells" were building up a map, not just registering visual input.
"I made the initial discovery over 40 years ago. It was met then with a lot of scepticism," the 74-year-old O'Keefe said. "And then slowly over years, the evidence accumulated. And I think it's a sign of recognition not only for myself and the work I did, but for the way in which the field has bloomed."
What is vital, however, is that the knowledge about the brain's positioning system can also help understand what causes loss of spatial awareness in stroke patients or those with brain diseases like dementia, of which Alzheimer's is the most common form and which affects 44 million people worldwide.
In 1996, Edvard Moser and May-Britt Moser, now based in scientific institutes in the Norwegian town of Trondheim, worked with O'Keefe to learn how to record the activity of cells in the hippocampus. In 2005, they identified another type of nerve cell in the entorhinal cortex region in the brains of rats that functions as a navigation system. These so-called "grid cells," they discovered, are constantly working to create a map of the outside world and are responsible for animals' knowing where they are, where they have been, and where they are going.
The Nobel Assembly said the laureates' discoveries marked a shift in scientists' understanding of how specialized cells work together to perform complex cognitive tasks. They have also opened new avenues for understanding cognitive functions such as memory, thinking, and planning.
The finding, a fundamental piece of research, explains how the brain works but does not have immediate implications for new medicines, since it does not set out a mechanism of action.
For our relevant BCC Research reports on Alzheimer’s, visit the following links: