Fig. 5: Synchronous activity close to salient locations in animals with recovery of memory deficits.

A Network schematic showing spatial distribution and correlation of pairwise firing (Pearson’s correlation of ΔF/F traces) between all imaged place cells (PCs, green) and non-coding cells (NCs, gray) in an exemplary field of view. Highly correlated neurons (95th percentile) are connected by lines. Line width and opacity represent connectivity strength, and colors identify functional coding of cell pairs (gray: NC – NC pairs; yellow: NC – PC pairs, green: PC – PC pairs). B Mean correlation of pairwise activity between all imaged neurons in the three outcome groups (Sham, n = 11; Recovery, n = 5; No-Recovery, n = 4) across experimental phases. C Cumulative distribution function (CDF) of pairwise ΔF/F activity between place cell and non-coding cell pairs in the healthy condition. Red dashed line indicates the 95^th percentile, at which the difference between place cells and non-coding cells is largest. D Percentage of place cell pairs in the 95^th pool of cells with highly correlated activity shows a loss of place cells pairs in the No-Recovery group. Error bars depict standard error. Dashed lines represent chance level of a uniform distribution (5%). E 95th percentile of correlation coefficients of spatial activity maps between all imaged neurons. F Histograms of place field distributions of highly correlated place cells in the three different outcome groups (Sham, Recovery, No-Recovery) and the different time points (healthy, early and late after stroke). Histograms show how many place fields were located far from, close to, or in the reward zones of the virtual reality corridor. G Analysis of the histograms in F reveal that initially, highly correlated place cells in sham mice are in particular found in reward zones, while in the late phase after stroke, animals of the Recovery group show a significant concentration of place fields close to reward zones compared to other corridor regions and compared to sham. Bar plots in D and G are presented as mean values +/- SEM. Boxplots are drawn with the box extending from the 25th to 75th percentiles, with the centre line at the median. Whiskers reach to the minimum and maximum values of the distribution. Group differences were evaluated with two-way repeated measures ANOVA with the Greenhouse-Geisser correction and Tukey-Kramer multiple comparisons test. Asterisks indicate significances: *p < 0.05, **p < 0.01, ***p < 0.001.