Occurrence of synchrony in the network model. The z statistic of synchrony depends on the number of neurons (N), distance parameter (R), and fraction of up-down potentials (p+). Twelve simulations/data point; z calculated from 2,500 to 3,500 ms; shown are arithmetic means. Initial phases were either uniformly distributed (thin lines) or fully synchronized (thick lines). p+ indicated above A–C. U, uniform distribution.