The hippocampus is essential for some types of memory, but its specific role remains conjectural. While studies on place cells have supported the hypothesis that the hippocampus provides a spatial substrate for episodic memory, recent engram studies have shown that optogenetic activation of a subset of hippocampal neurons that lack a temporal structure of the spike sequences can also induce memory-associated behavior. In this short review, I discuss the various lines of research that have led to different views of the role of the hippocampus in memory and propose a plausible interpretation of the findings that incorporates two influential theories.
Keywords: Contextual memory; Hippocampus; Immediate early genes; Memory engram; Memory trace; Place cell; c-Fos.
Copyright © 2020 The Author. Published by Elsevier B.V. All rights reserved.