Figure 2.

Repertoire of spatiotemporal patterns in control and topographical cultures

(A) Representative examples of spatiotemporal activity fronts for controls, tracks and squares configurations. For the two latter, both young and mature developmental stages are shown for the same culture. Each colored dot in the image plots is an active ROI, with the color coded according to the time of activation (from black to yellow). Gray regions indicate absence of active ROIs. Activity in controls always comprises the entire network and propagates fast ($\Delta t\simeq 0.2-0.3$ s). For lines and squares, activity switches between few sections of the culture or its whole extent, and much slowly ($\Delta t\simeq 1-3$ s). The number on the top-left corner of each panel identifies the burst, whereas the big white dot signals the origin of activity. For the tracks configuration, the image plots are drawn for the topographical tracks to coincide with the vertical direction. For the squares configuration, the motifs are aligned with the image borders.

(B) Classification of burst sizes and propagation. Each band corresponds to a burst which are ordered according to their similarity. The width of a band indicates the number of ROIs involved in the burst, whereas its color indicates the propagation time. Bands with similar color scheme portray bursts with akin spatiotemporal structure. The numbers within a gray circle indicate the position of the bursts represented in (A). The doted black lines separate the different groups of bursts.

(C) Detailed classification in the form of similarity matrix and following the same organization as in (B). The brighter the color, the higher the similarity among bursts. White dashed boxes identify the groups of similar bursts.