Reactivation of memory-associated neurons induces downstream suppression of competing neuronal populations

Inducing apparent memory recall by tagging and optogenetically reactivating cells in the hippocampus was demonstrated over a decade ago. However, the hippocampal dynamics resulting from this reactivation remain largely unknown. While calcium imaging is commonly used as a measure of neuronal activity, GCaMP, the most common calcium indicator, cannot be used with optogenetic neuronal reactivation because both require blue light excitation. To resolve this overlap, we demonstrate optogenetic reactivation with a red-shifted opsin, ChrimsonR. We then conduct dual-color calcium imaging in CA1 during memory reactivation in DG. In addition to measuring population dynamics in CA1, CA1 cells tagged during the original experience were identified. In the fear conditioned animals (FC+), non-tagged cells in CA1 decreased their firing rate during stimulation, while tagged cells maintained their activity level. In the FC+ animals, as the behavioral effect of stimulation decreased across days, so did th..., These data were collected using 2-photon imaging during optogenetic memory reactivation. Behavioral data were collected during imaging.
Calcium transients were extracted using CaImAn as described in the manuscript. The mCherry images were aligned to the imaging data and corrected for any bleed through. Traces were manually inspected to ensure only cells with sufficient signal were included. The available data are the results of this processing, raw data are available upon request. , , # Reactivation of memory-associated neurons induces downstream suppression of competing neuronal populations

[https://doi.org/10.5061/dryad.xsj3tx9q0](https://doi.org/10.5061/dryad.xsj3tx9q0)

## Overview

These data were collected from mouse hippocampus during a behavioral licking task and during optogenetic stimulation. Prior to the behavioral and imaging task, mice were trained to lick from a lick port as much as they'd like during a 15 minute session. Each mouse received one session per day. Additionally, mice had an experience tagged; tagged neurons express mCherry in CA1 and ChrimsonR-mCherry in DG. GCaMP was virally injected to CA1. These datasets are the imaging and behavioral data collected during optogenetic memory reactivation.

## Description of the data and file structure

This dataset totally consists of 15 data files (firing rate and mouse licking data). Both behavioral data and imaging data are contained in this dataset. The behavioral data is organized by mouse, while ...,