Fig. 2

Population data of neuronal cell-subtype specific correlation. a–d Population histograms showing the within-type correlation distributions in Pyr (a), PV (b), VIP (c) and SST (d) neurons, respectively. Each histogram plotted the fraction of active cells against the percentage of correlated active neighbours (see Methods). Note the difference in CC distributions between neuron types: Pyr neurons (a) exhibited a broad and continuous distribution, showing a versatile correlation profile. PV INs (b) were spontaneously active and highly synchronised, almost all PV INs was strongly correlated with every other PV IN in the same FOV. VIP INs (c) were also highly synchronised with each other, significantly stronger than Pyr neurons but weaker than PV INs. SST INs (d), on the other hand, showed a subtype specificity. One subpopulation (red, Subtype I) were spontaneously active, but uncorrelated to nearly any SST neighbours. Subtype II SST cells (dark blue), however, were strongly coupled. e–h. CC distributions in Pyr (e), PV (f), VIP (g) and SST (h) neurons, respectively. Thin lines represented data from individual animals. Note the long-tailed distribution in SST INs, which was in line with the existence of two subtypes. i Relationships between CC strengths and corresponding spatial distance in Pyr (green), PV (light blue), VIP (gray) and SST subtype I (red) and II (dark blue) neurons, respectively (two-way ANOVA, p < 0.001). j Average % of correlated neighbours across animals in Pyr (green), PV (light blue), VIP(green) and SST (black) neurons, respectively. Statistical significance was colour-coded. k Average CC in Pyr (green), PV (light blue), VIP(green) and SST (black) neurons, respectively. **p < 0.01, n.s.: not significant. Error bar: s.e.m.