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:
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