Magnetic fields light up 'GPS neurons', scientists say

By Jason PalmerScience and technology reporter, BBC News
Researchers have spotted a group of 53 cells within pigeons' brains that respond to the direction and strength of the Earth's magnetic field.

The question of how birds navigate using - among other signals - magnetic fields is the subject of much debate.

These new "GPS neurons" seem to show how magnetic information is represented in birds' brains.

However, the study reported by Science leaves open the question of how they actually sense the magnetic field.

David Dickman of the Baylor College of Medicine in the US set up an experiment in which pigeons were held in place, while the magnetic field around them was varied in its strength and direction.

Prof Dickman and his colleague Le-Qing Wu believed that the 53 neurons were candidates for sensors, so they measured the electrical signals from each one as the field was changed.
Read on:  http://www.bbc.co.uk/news/science-environment-17855194