Figure 7. Flexible electronics.

a. Schematic depicting flexible electronics on the surface of an organoid. b. Optical image of a cortical spheroid enclosed in a 3D flexible bioelectronics designed for electrophysiological recording. c. Confocal microscope image of the spheroid in a similar 3D mesostructure, neurofilament (red), GFAP (green), Nissl (magenta), DAPI (blue), and autofluorescence from the parylene-C in bioelectronics (blue). Dashed circles indicate the approximate positions of microelectrodes in a corresponding functional system. d. 3D illustration of the positions of the microelectrodes across the surface of the spheroid. e. 3D plot of time latency associated with traces in the blue box of (f). f. Representative field potentials were recorded from all 25 microelectrodes in the system. g. Overlaid plots of 30 spikes from channels 1, 2, and 4. h. Network activity of day 8 and suppressed behavior resulting from the application of TTX. i. Weighted mean firing rate (the spike rate multiplied by the number of active electrodes) is representative of 2 min at each condition. n = 3 spheroids; *P < 0.05; two-tailed paired t-test; means ± SEM. j-l, Illustrations, optical images, and raster plots (j) before and (k) after transection of the neurite bridge that joins the spheroids of this assembloid and (l) recovery after transection. Figure 7a adapted from Passaro et al.²¹, Figures 7b-l adapted from Park et al.⁴⁷.