(A response to ‘Alzheimer’s Disease Discovery Leads To Nobel Prize‘ and other similar articles)
- Activities of 8 place cells recorded while the rat ran back and forth through along the track. Each dot is an action potential, and each color is a different cell. Credit Stuartlayton via Creative Commons 3.0
Last week, the Nobel Prize in Physiology or Medicine was awarded for the discovery of the brain’s navigation system. When breaking the news, nearly every report – including the – mentioned the relevance of this research to understanding and potentially treating Alzheimer’s disease. But what really is the relationship between understanding how our brain allows us to navigate and our ability to combat the complex pathology of Alzheimer’s disease?
John O’Keefe, May-Britt Moser, and Edvard Moser won the prize for their discoveries of ‘place cells‘ and ‘grid cells’. These neurons reside in the hippocampus and entorhinal cortex respectively, where their combined activities constitute our ability to remember our environment and navigate through it. For example, each place cell becomes active when you are in specific parts of a room or space (see image). It is thought that the activity of these cells actually is the knowledge of where you are! Their relationship with Alzheimer’s disease is both symptomatically evident and pathologically verified: common early symptoms of the disease include being lost and disoriented, and it is well established that the hippocampus and entorhinal cortex are usually the first brain regions affected in the disease. However, knowing what information these neurons encode has not provided an explanation for what causes the disease, how it manifests itself in the brain, or how we could treat it. While it is possible that understanding how these neurons function may help to solve Alzheimer’s disease, so far there is no evidence that directly supports this to be true.
So then why is this research Nobel Prize worthy? In fact, the reason has little to do with Alzheimer’s disease. The discovery of how place cells and grid cells form the brain’s navigation system is so significant because it is really the first bridge that neuroscientists have built between cellular activities and higher cognitive functions. In the elusive quest to understand how thoughts, emotions, and behavior arise from brain cells simply obeying physical and chemical laws, place and grid cells provide a beautiful example for how we hope to understand the rest of the brain.
Edited by Shay Neufeld.
for a more comprehensive explanation of the award and how place and grid cells work.