Extended Data Figure 8: Additional analyses: estimation of event onsets using fast non-negative deconvolution, and correlated pair analysis.

a, Example pairings of the original GCaMP6m trace (top traces), with the deconvolved trace (bottom traces), shows reliable estimation of event onset from deconvolved data (deconvolution algorithm and parameters detailed further in Methods). Scale bar: 150% ΔF/F, 10 s. b, Original GCaMP6m traces from a representative synchronous event in one animal (left), paired with the deconvolved traces for that same synchronous event (right). Scale bar: 300% ΔF/F, 10 s. c, The highest-degree node (neuron with the greatest number of correlated pairs) in the day 3 fear context had significantly more correlated pairs than the highest degree node in the day 3 neutral context, significant across n = 5 mice (58.8 versus 33.2 pairs, P < 0.01, paired t-test). d, Temporal relationship of HC neuron activity onset (set to time 0) compared with onset activity of correlated pairs (binned into 333 ms preceding or succeeding HC activity); n = 48 HC neurons. HCs were more likely to lead than lag their correlated pairs (58.5 ± 20% leading versus 24.4 ± 10% lagging; P < 0.01, unpaired t-test). e, Significant synchronous activity (defined in Methods) quantified across five mice: number of synchronous events in the fear context was significantly greater than in the neutral context (5.8 ± 2.9 events in fear context versus 1.2 ± 1.1 in neutral context; P < 0.01, paired t-test). *P < 0.05, **P < 0.01, ***P < 0.001.