Fig. 4

Changes in Ca²⁺activity in population of dendrites correlates with local changes in sigma–beta power during SWS. a Examples of PD time course for different frequency bands from the EEG surrounding the Ca²⁺ imaging site (i.e., EEG-FP). Traces are plotted against the sigma+dendritic Ca²⁺ PD trendlines (dotted lines, inset). b Illustration of the cross-correlation time–frequency analysis (see Methods). c Time–frequency analysis for dendritic recordings. Results for local (FP, left) and distant (FF, right) EEGs are represented. Energy heat maps (upper graphs) with corresponding P-values (bottom graphs) for a ±2 s cross-correlation time window (see Supplementary Fig. 6b for L2/3 results). d Illustration of the ΔPD (PD 3rd−PD 1st) calculation. e Correlation coefficient between the mean (across SWS episodes in each animal) Ca²⁺ and EEG frequency bands ΔPDs (n = 11). Results are shown separately for frontal and parietal EEGs. *P < 0.05, **P < 0.01 and ***P < 0.001, Pearson’s correlation. f Corresponding scatter plots for sigma and beta frequency bands for EEG-FP (values represent individual animals). Correlations were not significant for frontal EEG (vs. EEG-FF, sigma: r = 0.48, P = 0.13; beta: r = 0.52, P = 0.1)