SummaryThe dentate gyrus (DG) is crucial for behaviorally discriminating similar spatial memories, predicting that dentate gyrus place cells change (“remap”) spatial tuning (“place fields”) for memory discrimination. This prediction was never tested, although DG place cells remap across similar environments without memory tasks. We confirm this prior finding, then demonstrate that DG place fields do not remap across spatial tasks that require DG-dependent memory discrimination. Instead of remapping, place-discriminating discharge is observed transiently amongst DG place cells, particularly where memory discrimination is most necessary. The DG network signals memory discrimination by expressing distinctive sub-second network patterns of co-firing amongst principal cells at memory discrimination sites. This is accompanied by increased coupling of discharge from excitatory principal cells and inhibitory interneurons. Instead of remapping, these findings identify that memory discrimination is signaled by sub-second patterns of correlated discharge within the dentate network.eTOC blurbvan Dijk and Fenton report that dentate gyrus place cells signal memory discrimination not by remapping, but by variable sub-second patterns of coordinated place cell network discharge and enhanced discharge coupling between excitatory and inhibitory neurons, at sites of memory discrimination.HighlightsDentate gyrus-dependent memory discrimination does not require place cell remappingDentate neural correlates of pattern discrimination are transient, lasting secondsSub-second dentate network discharge correlations signal memory discriminationDentate excitatory-inhibitory coupling is increased at memory discrimination sites
Hippocampal functional organization: A microstructure of the place cell network encoding space
