Jake Ormond, Simon A. Serka, Joshua P. Johansen. Enhanced reactivation of remapping place cells during aversive learning. Journal of Neuroscience 3 January 2023, JN-RM-1450-22; DOI: 10.1523/JNEUROSCI.1450-22.2022

Abstract
“Study of the hippocampal place cell system has greatly enhanced our understanding of memory encoding for distinct places, but how episodic memories for distinct experiences occurring within familiar environments are encoded is less clear. We developed a spatial decision-making task in which male rats learned to navigate a multi-arm maze to a goal location for food reward while avoiding maze arms in which aversive stimuli were delivered. Task learning induced partial remapping in CA1 place cells, allowing us to identify both remapping and stable cell populations. Remapping cells were recruited into sharp wave ripples (SWRs) and associated replay events to a greater extent than stable cells, despite having similar firing rates during navigation of the maze. Our results suggest that recruitment into replay events may be a mechanism to incorporate new contextual information into a previously formed and stabilized spatial representation.”

SIGNIFICANCE STATEMENT:

“Hippocampal place cells provide a map of space which animals use to navigate. This map can change to reflect changes in the physical properties of the environment in which the animal finds itself, and also in response to non-physical contextual changes, such as changes in valence of specific locations within that environment. We show here that cells which change their spatial tuning after a change in context are preferentially recruited into SWR-associated replay events compared to stable non-remapping cells. Thus, our data lend strong support to the hypothesis that replay is a mechanism for the storage of new spatial maps.”

Jake Ormond, Simon A. Serka, Joshua P. Johansen. Enhanced reactivation of remapping place cells during aversive learning. Journal of Neuroscience 3 January 2023, JN-RM-1450-22; DOI: 10.1523/JNEUROSCI.1450-22.2022