Extended Data Figure 7: Spatial and temporal organization of HC neurons.

a, Plot of mean pairwise correlation versus mean pairwise distance averaged over all FOVs (all days and all contexts) from all five mice. It was possible to detect a significant but weak relationship between mean correlation and distance (Spearman’s correlation = −0.66, P = 0.01), which could be a reflection of fine-scale spatial clustering as might be expected of recurrent circuits in CA3, but would also probably include residual crosstalk between regions of interest (ROIs) due to brain motion and common neuropil signal, which is expected and not significantly different from what has been previously observed in the hippocampus³. b, Plot of the number of correlated pairs versus pairwise distance for all neurons (black line), and HC neurons only (grey line). More correlated pairs were found at greater distances for HC neurons (Spearman’s = 0.84, P = 0.002 for HC neurons; Spearman’s correlation = 0.23, P = 0.43 for all neurons). c, Cumulative distributions showing fraction of HC neurons (y-axis) with onset times at various latencies across the time course of synchronous events (x-axis) averaged across all mice, compared to response latencies of non-HC neurons. HC neuron activity appeared significantly earlier than for non-HC neurons during synchronous events (P < 0.001, Kolmogorov–Smirnov two-tail test, κ = 0.664; note the horizontal resolution of the plot is inversely proportional to length of the synchrony window, and dependent on frame duration; for instance, a 10-s-long synchrony window with frame duration of 333 ms corresponds to a 3.33% resolution per frame).