Fig. 2: Network dynamics of vmDA neurons.
a Representative image of a bright field recording at D80 (isoPD1) using the calcium imaging assay. Scale bar is 100 μm. Regions of interest were manually selected for each neuron (diameter 10 μm; color circles) to obtain the normalized calcium fluorescence time series of spontaneous activity, DFF (%) \(\equiv 100 \cdot(F - F_0)/F_0\), with F0 the fluorescence signal of the neuron at rest. The green box illustrates the fast rise of fluorescence upon activation that procures the spiking onset time (arrowhead). The dashed black boxes illustrate coordinated neuronal activity that shape network bursts when several neurons are involved. b Average neuronal activity along maturation for the different cell lines. Data points are expressed as mean±SD. Trend lines are linear regressions. The number of cultures used in each condition and timepoint were: D35 (CTR: n = 3; isoPD1: 3; PD1: 4; PD2: 4); D50 (3; 9; 9; 5); D80 (3; 9; 8; 5). c Representative raster plots (top) and global network activity (GNA, bottom) for CTR (SP11), isoPD1, and PD1 (SP12) neuronal cultures at D80. Each plot shows 5 min of recording. Peaks in the GNA reveal network bursts (blue dots). Extreme bursting events (red dots) are those that are above a threshold (red dotted line) set as 95% confidence interval of CTR bursts’ distribution. CTR and isoPD1 networks show a relative low percentage of extreme events, which contrasts with the rich abundance of them in PD1 networks. d Ratio of extreme events for all studied cell lines at D50 and D80. The colored boxes are a guide to visualize the distributions, which show the mean ± SD and the individual realizations (dots). For panels (b) and (d), the number of independent experiments for each condition and timepoint are D35 (CTR: n = 3, isoPD1: 3, PD1: 4, PD2: 4); D50 (3, 9, 9, 5); D80 (3, 9, 8, 5). ***p < 0.001 (ANOVA with multiple comparison analysis).
