Fig. 4: 15q11.2 deletion decreases firing rate and bursting and delays synchrony in culture networks.

A Raster plots of spikes determined from voltage recordings from 16 electrodes from representative single wells of control (top) and 15q11.2 deletion (bottom) cultures at DIC 65, 106 and 154. Each row is data from a single electrode. Single spikes for a given electrode are represented by black vertical marks. Blue vertical lines are spikes on a single electrode meeting criterion for an electrode burst (5 spikes occurring within 100 ms). Black tracing at the top of each panel represents relative spikes per time per second across the entire well. Time scale bar is 50 s. Analysis of four control and three 15q11.2 deletion lines over at least 3 independent differentiations for B weighted mean firing rate (Two-way ANOVA P < 0.0001), C percent of spikes that occur in bursts (burst percentage) (Two-way ANOVA P < 0.0001), Tukey’s multiple comparison test and D area under normalized cross correlogram (AUNCC) as a quantification of synchronization (TwoWay ANOVA P < 0.0001). Mean values ± SEM are indicated by symbols. Linear regressions (solid lines) with 95% confidence intervals (dashed lines) are in grey and blue. Two-way ANOVA P < 0.0001. Tukey’s multiple comparisons * = P < 0.05. For B and C, Tukey’s multiple comparison’s testing indicates significance from P < 0.01 to P < 0.0001  for all data points to right of the vertical dashed line.