The Brain’s GPS – How Place Cells Map Your World

Have you ever wondered how you instinctively know your way around a familiar room, even in the dark? Neuroscientists have uncovered a remarkable system in the brain that makes this possible. Deep inside the hippocampus, a region essential for memory and spatial awareness, are specialized neurons called place cells. 

These cells fire only when you are in a specific location in your environment, essentially forming a mental map of the world around you. First discovered in rats by neuroscientist John O'Keefe in 1971, place cells provided the first real evidence of spatial representation in the brain. O'Keefe’s discovery showed that different neurons would activate as an animal moved through different parts of a space, forming a dynamic internal map.

This breakthrough earned O’Keefe and collaborators May-Britt and Edvard Moser the Nobel Prize in Physiology or Medicine in 2014 (The Nobel Assembly at Karolinska Institutet, 2014). But place cells do not work alone. In 2005, the Mosers discovered another set of neurons called grid cells, located in the entorhinal cortex. These cells activate in a pattern that resembles a hexagonal grid, providing a coordinate system that allows for more precise spatial navigation (Hafting et al., 2005). Together, grid and place cells allow us to recognize locations, remember routes, and navigate through both familiar and new environments.

This internal GPS is not just useful, but it is vital to our survival. In the early stages of Alzheimer’s disease, patients often experience disorientation and trouble navigating familiar places. This is partly because the hippocampus and entorhinal cortex are among the first regions to be affected, disrupting the brain’s mapping system. The next time you effortlessly find your way home, remember: your brain is constantly mapping, recalibrating, and navigating without you even noticing..

Sources:

The Nobel Assembly at Karolinska Institutet. (2014). The Nobel Prize in Physiology or Medicine 2014. https://www.nobelprize.org/prizes/medicine/2014/summary/

Hafting, T., Fyhn, M., Molden, S., Moser, M. B., & Moser, E. I. (2005). Microstructure of a spatial map in the entorhinal cortex. Nature, 436(7052), 801–806. https://doi.org/10.1038/nature03721