Grid cells produce exceptionally regular firing patterns as animals navigate in 2D spaces. Two new studies show that in flying and climbing animals, the activity patterns of these cells in 3D space are irregular. These results reveal an unexpected way in which the brain represents spatial location.
Perception of space is crucial for cognition. Many of our actions are movements through space; many of our memories are linked to a specific place. Over several decades, there has been a concerted effort to understand how neural activity represents spatial location. In this line of work, there is a pervasive challenge: space is three-dimensional (3D), whereas most animals in laboratory experiments run, walk or crawl on flat surfaces. Now, two papers—in Nature1 and Nature Neuroscience2—extend our knowledge of spatial coding into the third dimension. To achieve this goal, these studies use innovative experiments in flying and climbing animals.
Aronov, D. Disordered grids in the third dimension. Nat Neurosci (2021). https://doi.org/10.1038/s41593-021-00925-2