Figure 3

Synchronous activity reemerges following semi-phasic, periodic ACh applications. a) Sync Ratio over time in one experiment (grey; same data after smoothing with a five-point kernel is shown in black), performed in an open-loop regime. ACh pulses were delivered once every five minutes, starting at t =5 minutes. Note the high values of the Sync Ratio in the period preceding ACh applications (initial conditions, obtained during the period defined as phase II in Figure 1c; see also Additional file 1: Figure S1) and the huge reduction in Sync Ratio values once ACh applications were initiated. Insets: examples of one-minute raster plots from early (left) and late (right) stages of the experiment. b) Enlarged one-hour sections of the plot shown in a from early (left) and late (right) stages of the experiment. Red arrows denote application times. c) Changes in Sync Ratio over time in five separate experiments similar to the experiment shown in a. For each experiment, Sync Ratio values, averaged over 30 minutes, were normalized to the average Sync Ratio measured during the 4 hour period preceding ACh application (initial conditions). Average ± SEM for five experiments. d) Total firing rates measured from all electrodes, averaged over 30 minute intervals, normalized for each experiment to the average firing rate measured during the 4 hour period preceding ACh application (Initial conditions). Note that the initiation of ACh applications was not associated with changes in overall firing rates. Average ± SEM for five experiments. ACh, acetylcholine; SEM, standard error of the mean.