Extended Data Fig. 5: NSC-Chimeroids present uniform spatial distribution across donors.

a, Slice #1. Spatial plot of Slide-seq data from 2-mo MD-NSC Chimeroids (Mix 5), coloured by maximal donor contribution via Census-seq. b, Spatial plots showing donor prediction weights. c, Spatial plot of Slide-seq data from 2-mo NSC-Chimeroids (Mix 5), coloured by RCTD-assigned cell type. d, Spatial plots showing cell type prediction weights. e, Slice#2. Same as a. f, Slice#2. Same as b. g, Slide#2. Same as c. h, Slide#2. Same as d. i, Representative organoid placed on a Multielectrode Array (MEA). j, Representative activity map of a MD-NSC Chimeroid network burst at 4mo, where each pixel of the map represents an electrode (left) and example action potential traces from the electrodes highlighted in the activity map (right). k, Representative raster plot showing the firing activity of active electrodes (139, defined as electrodes with a mean firing rate >0.15 spikes/s inside the outline of the organoid) over a 15 min recording. Network bursts start to appear around 5 mins. l, Effect of AMPA and NMDA blockers (D-AP5, 150 µM; DNQX 60 µM) on neuronal activity/network bursts (left panel); network bursting activity of 4 recorded NSC-Chimeroids (right panel). Some icons were created using BioRender.