Edvard Moser

Edvard Moser, together with his then-wife May-Britt Moser, discovered grid cells in the medial entorhinal cortex in 2005. These neurons fire in a hexagonal lattice pattern as an animal moves through space, providing the brain with an internal metric map for measuring distances and directions. The discovery was made at NTNU in Trondheim and published in the journal Nature.

In addition to grid cells, the Mosers' lab identified head direction cells, which fire based on which way the head is pointing, and speed cells, which encode running speed. They also found border cells that fire when the animal is near environmental boundaries. Together, these cell types form an integrated positioning system that feeds into the place cells in the hippocampus.

The Mosers discovered grid cells by recording the electrical activity of individual neurons in the medial entorhinal cortex of freely moving rats using microelectrodes implanted in the brain. They were initially investigating how the entorhinal cortex communicates with the hippocampal place cells when they noticed the regular triangular firing pattern. The discovery required both sophisticated electrode technology and custom software to track the animal's position and correlate it with neural firing in real time.

After the Nobel Prize, Edvard Moser has continued to investigate the neural circuitry underlying spatial cognition at the Kavli Institute for Systems Neuroscience at NTNU. His lab uses advanced techniques including two-photon calcium imaging to monitor large populations of grid cells simultaneously, revealing how the network of grid cells organizes into functional modules. He has also expanded into studying how the brain organizes time and episodic memory.