Network-wide burst propagation time as a function of culture age.

<p>Bar chart shows the median burst propagation time (from all transient networks of all cultures at each age), values outside the 5^th to 95^th percentiles were removed as outliers, giving <i>n</i> = 6–8 for each age). Error bars show 25^th and 75^th percentiles. A (network-wide) burst was defined as a near-simultaneous (within 250 ms) occurrence of channel bursts on multiple (≥4) channels. A channel was considered to display bursting activity if ≥4 spikes were detected in 100 ms. For each channel included in the burst, recruitment time was the timestamp of the first spike in the ≥4 spikes in 100 ms sequence. Burst propagation time was calculated as the time to recruit all channels in a network-wide burst. At DIVs 28 and 35, this time was significantly lower than at DIV 14.