title: A Multiplexed, Heterogeneous, and Adaptive Code for Navigation in Medial Entorhinal Cortex.
abstract: Medial entorhinal grid cells display strikingly symmetric spatial firing patterns. The clarity of these patterns motivated the use of specific activity pattern shapes to classify entorhinal cell types. While this approach successfully revealed cells that encode boundaries, head direction, and running speed, it left a majority of cells unclassified, and its pre-defined nature may have missed unconventional, yet important coding properties. Here, we apply an unbiased statistical approach to search for cells that encode navigationally relevant variables. This approach successfully classifies the majority of entorhinal cells and reveals unsuspected entorhinal coding principles. First, we find a high degree of mixed selectivity and heterogeneity in superficial entorhinal neurons. Second, we discover a dynamic and remarkably adaptive code for space that enables entorhinal cells to rapidly encode navigational information accurately at high running speeds. Combined, these observations advance our current understanding of the mechanistic origins and functional implications of the entorhinal code for navigation. VIDEO ABSTRACT.
authors.affiliation: Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Applied Physics, Stanford University, Stanford, CA 94305, USA. Electronic address: khardcas@stanford.edu.
authors.forename: Kiah
authors.initials: K
authors.lastname: Hardcastle
authors.affiliation: Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Applied Physics, Stanford University, Stanford, CA 94305, USA.
authors.forename: Niru
authors.initials: N
authors.lastname: Maheswaranathan
authors.affiliation: Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Applied Physics, Stanford University, Stanford, CA 94305, USA.
authors.forename: Surya
authors.initials: S
authors.lastname: Ganguli
authors.affiliation: Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305, USA. Electronic address: giocomo@stanford.edu.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Giocomo
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D018728:Entorhinal Cortex / Q000502:physiology*; D005260:Female; D006257:Head; D008297:Male; D008810:Mice, Inbred C57BL; D008959:Models, Neurological; D009043:Motor Activity / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*; D013826:Theta Rhythm / Q000502:physiology*
keywords: Multiplexed-coding; adaptive coding; computational models of spatial coding; encoding mode; entorhinal cortex; spatial navigation; tuning heterogeneity