Superficial layers of the medial entorhinal cortex replay independently of the hippocampus Journal Article


Author(s): O'Neill, Joseph; Boccara, Charlotte N; Stella, Federico; Schönenberger, Philipp; Csicsvári, József
Article Title: Superficial layers of the medial entorhinal cortex replay independently of the hippocampus
Affiliation IST Austria
Abstract: The hippocampus is thought to initiate systems-wide mnemonic processes through the reactivation of previously acquired spatial and episodic memory traces, which can recruit the entorhinal cortex as a first stage of memory redistribution to other brain areas. Hippocampal reactivation occurs during sharp wave-ripples, in which synchronous network firing encodes sequences of places.We investigated the coordination of this replay by recording assembly activity simultaneously in the CA1 region of the hippocampus and superficial layers of the medial entorhinal cortex. We found that entorhinal cell assemblies can replay trajectories independently of the hippocampus and sharp wave-ripples. This suggests that the hippocampus is not the sole initiator of spatial and episodic memory trace reactivation. Memory systems involved in these processes may include nonhierarchical, parallel components.
Journal Title: Science
Volume: 355
Issue 6321
ISSN: 0036-8075
Publisher: American Association for the Advancement of Science  
Date Published: 2017-01-13
Start Page: 184
End Page: 188
Sponsor: This work was supported by a European Research Council Consolidator Grant (281511).
DOI: 10.1126/science.aag2787
Open access: no