Hippocampal Global Remapping Can Occur without Input from the Medial Entorhinal Cortex

• Main Authors: Magdalene I. Schlesiger, Brittney L. Boublil, Jena B. Hales, Jill K. Leutgeb, Stefan Leutgeb
• Format: Article
• Language: English
• Published: Elsevier 2018-03-01
• Series: Cell Reports
• Online Access: http://www.sciencedirect.com/science/article/pii/S2211124718302924

Summary: The high storage capacity of the episodic memory system relies on distinct representations for events that are separated in time and space. The spatial component of these computations includes the formation of independent maps by hippocampal place cells across environments, referred to as global remapping. Such remapping is thought to emerge by the switching of input patterns from specialized spatially selective cells in medial entorhinal cortex (mEC), such as grid and border cells. Although it has been shown that acute manipulations of mEC firing patterns are sufficient for inducing hippocampal remapping, it remains unknown whether specialized spatial mEC inputs are necessary for the reorganization of hippocampal spatial representations. Here, we examined remapping in rats without mEC input to the hippocampus and found that highly distinct spatial maps emerged rapidly in every individual rat. Our data suggest that hippocampal spatial computations do not depend on inputs from specialized cell types in mEC. : Schlesiger et al. find that specialized spatial cells in mEC are not required for generating distinct hippocampal maps across environments. Inputs to the hippocampus, therefore, do not need to be specialized for spatial coding to support hippocampal spatial computations. Keywords: episodic memory, medial entorhinal cortex, hippocampus, place cells, grid cells, border cells, global remapping, hippocampal maps