A, cross-correlation of the onset of a simple spike (SS) pause during spontaneous activity for one coupled PC pair (SS pause on versus SS pause on). B, the cessation of a pause (SS pause off versus SS pause off). C, the onset of a pause in one PC and the cessation of a pause in the other PC (SS pause on versus SS pause off). The onset and cessation of a simple spike pause was more likely to occur synchronously than the onset of a pause in one PC and the cessation of a pause in the other PC (5 ms bins, scale bar 0.05 probability for A–C). D, the means (±s.e.m.) of the change in simple spike pause T0 probability (%) shown for all coupled and non-coupled PC pairs for each of the three different pause conditions. *P < 0.05.