title: Hippocampal Offline Reactivation Consolidates Recently Formed Cell Assembly Patterns during Sharp Wave-Ripples.
abstract: The ability to reinstate neuronal assemblies representing mnemonic information is thought to require their consolidation through offline reactivation during sleep/rest. To test this, we detected cell assembly patterns formed by repeated neuronal co-activations in the mouse hippocampus during exploration of spatial environments. We found that the reinstatement of assembly patterns representing a novel, but not a familiar, environment correlated with their offline reactivation and was impaired by closed-loop optogenetic disruption of sharp wave-ripple oscillations. Moreover, we discovered that reactivation was only required for the reinstatement of assembly patterns whose expression was gradually strengthened during encoding of a novel place. The context-dependent reinstatement of assembly patterns whose expression did not gain in strength beyond the first few minutes of spatial encoding was not dependent on reactivation. This demonstrates that the hippocampus can hold concurrent representations of space that markedly differ in their encoding dynamics and their dependence on offline reactivation for consolidation. VIDEO ABSTRACT.
authors.affiliation: MRC Brain Network Dynamics Unit, Department of Pharmacology, University of Oxford, OX1 3TH Oxford, UK. Electronic address: gido.vandeven@pharm.ox.ac.uk.
authors.forename: Gido M
authors.initials: GM
authors.lastname: van de Ven
authors.affiliation: MRC Brain Network Dynamics Unit, Department of Pharmacology, University of Oxford, OX1 3TH Oxford, UK.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Trouche
authors.affiliation: MRC Brain Network Dynamics Unit, Department of Pharmacology, University of Oxford, OX1 3TH Oxford, UK.
authors.forename: Colin G
authors.initials: CG
authors.lastname: McNamara
authors.affiliation: Department of Clinical Neurobiology, Medical Faculty of Heidelberg University and DKFZ, 69120 Heidelberg, Germany.
authors.forename: Kevin
authors.initials: K
authors.lastname: Allen
authors.affiliation: MRC Brain Network Dynamics Unit, Department of Pharmacology, University of Oxford, OX1 3TH Oxford, UK. Electronic address: david.dupret@pharm.ox.ac.uk.
authors.forename: David
authors.initials: D
authors.lastname: Dupret
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D058256:Brain Waves; D005106:Exploratory Behavior; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D051379:Mice; D009474:Neurons / Q000502:physiology*; D062308:Optogenetics; D012890:Sleep / Q000502:physiology*; D013037:Spatial Behavior