15 May 2015

How We Remember Routes: Nobel Laureates Open New Paths into the Brain's Secrets

How do you remember familiar routes? Do you have a GPS in your brain? According to the three scientists sharing the 2014 Nobel Prize in Physiology or Medicine, well, kinda — at least, if your brain works like a rat’s brain, that is.

John O'Keefe discovered the first component to the brain GPS in 1971: when a rat is in one place, a "place cell" activates in its brain. This is a type of nerve cell in the hippocampus: the area of the brain that handles memory, learning, and emotion. When the rat is in another place, a different nerve cell activates. These cells form a map.

In 2005, May-Britt Moser and Edvard I. Moser discovered that the place cells interact with grid cells, another kind of nerve cell that generates a coordinate system. These two types of nerve cells work together as a kind of internal GPS.

The winners of the 2014 Nobel Prize in Physiology or Medicine
Of course, we've known for some time that rats can navigate: the image of a lab rat running through a maze is a classic image of behavioral psychology. What we hadn't known before was how this process actually works in the brain — or where it actually happened.

What's more exciting is there's now evidence that humans have these place and grid cells, too. This has powerful implications for research into understanding why people with Alzheimer's disease get lost and can't recognize where they are.

But on an even grander level, the discovery of this internal GPS is a huge shift in our understanding of how large groups of highly specialized cells work in unison to perform elegantly orchestrated mental processes. And this, we hope, will lead to more insight into the mysteries of the brain.

This post is the result of an exercise at the 2015 Santa Fe Science Writing Workshop.