Fig. 6: mPFC engram cells activated by recall of observational CFC memory at the remote time point in the observer or demonstrator chamber.

a Strategy to label mPFC engram cells activated in the observer or demonstrator chambers. 28 days after observational CFC, observers were subjected to recall of observational CFC memory in the observer chamber (Obs #1) or demonstrator chamber (Dem #1), which labeled mPFC with mKate2. 1 day later, observers were subjected to a second recall test in either the observer chamber (Obs #2) or demonstrator chamber (Dem #2), which labeled mPFC with Arc. b Coronal section of mPFC engram cell labeling after recall of observational CFC memory. mKate2: Recall Test #1. Arc: Recall Test #2. Arrows; mKate2⁺Arc⁺ cells. c–f Percentages of Arc⁺ neurons in mKate2^- and mKate2⁺ neurons in PLC in Obs #1/Obs #2 (non-shock) (c), Obs #1/Obs #2 (Obs CFC) (d), Dem #1/Dem #2 (Obs CFC) (e), and Obs #1/Dem #2 (Obs CFC) (f). g Fold change analysis (actual/chance) comparing each behavioral condition. Dotted line; chance level (Fold change = 1). RT; Recall Test. Paired t test (c–f), and one-way ANOVA with Tukey test (g) were performed. *P < 0.05, and bars without asterisks did not reach significance (P > 0.05). Graphs are presented as box plots with minimum (lower whisker), 25th percentile (lower box bound), median (center), 75th percentile (upper box bound), and maximum (upper whisker) values indicated. Source data are provided as a Source data file.