Local transformations of the hippocampal cognitive map.
Grid cells are neurons active in multiple fields arranged in a hexagonal lattice and are thought to represent the ‘universal metric for space’. However they become non-homogeneously distorted in polarized enclosures which challenges this view. We found that local changes to the configuration of the enclosure induce individual grid fields to shift in a manner inversely related to their distance from the re-configured boundary. The grid remained primarily anchored to the unchanged stable walls and showed a non-uniform rescaling. Shifts in simultaneously-recorded co-localized grid fields were strongly correlated suggesting the readout of the animal’s position might still be intact. Similar field shifts were also observed in place and border cells albeit of greater magnitude and more pronounced closer to the configured boundary suggesting that there is no simple one-to-one relationship between these three different cell types