The Nobel Prize for physiology or medicine has been awarded to three scientists who discovered the brain's "GPS system".

UK-based researcher Prof John O'Keefe as well as May-Britt Moser and Edvard Moser share the award.

They discovered how the brain knows where we are and is able to navigate from one place to another.

Their findings may help explain why in Alzheimer's disease patients cannot recognise their surroundings.

"The discoveries have solved a problem that has occupied philosophers and scientists for centuries," the Nobel Assembly said.

Prof O'Keefe, from University College London, discovered the first part of the brain's internal positioning system in 1971.

He showed that a set of nerve cells became activated whenever a rat was in one location in a room.

A different set of cells were active when the rat was in a different area.

Prof O'Keefe argued these "place cells" - located in the hippocampus - formed a map within the brain.

In 2005, husband and wife team, May-Britt and Edvard, discovered a different part of the brain which acts more like a nautical chart.

These "grid cells" are akin to lines of longitude and latitude, helping the brain to judge distance and navigate.
http://m.bbc.com/news/health-29504761