Grid cells form a global representation of connected environments

Curr Biol. 2015 May 4;25(9):1176-82. doi: 10.1016/j.cub.2015.02.037. Epub 2015 Apr 23.


The firing patterns of grid cells in medial entorhinal cortex (mEC) and associated brain areas form triangular arrays that tessellate the environment [1, 2] and maintain constant spatial offsets to each other between environments [3, 4]. These cells are thought to provide an efficient metric for navigation in large-scale space [5-8]. However, an accurate and universal metric requires grid cell firing patterns to uniformly cover the space to be navigated, in contrast to recent demonstrations that environmental features such as boundaries can distort [9-11] and fragment [12] grid patterns. To establish whether grid firing is determined by local environmental cues, or provides a coherent global representation, we recorded mEC grid cells in rats foraging in an environment containing two perceptually identical compartments connected via a corridor. During initial exposures to the multicompartment environment, grid firing patterns were dominated by local environmental cues, replicating between the two compartments. However, with prolonged experience, grid cell firing patterns formed a single, continuous representation that spanned both compartments. Thus, we provide the first evidence that in a complex environment, grid cell firing can form the coherent global pattern necessary for them to act as a metric capable of supporting large-scale spatial navigation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Entorhinal Cortex / cytology
  • Entorhinal Cortex / physiology*
  • Environment
  • Male
  • Rats
  • Spatial Behavior / physiology*