Fig. 5

Propagation velocity of the signal between neuronal spheroids cultured on SCAD devices. (A) (a) Two spheroids on the seeding jig in the SCAD device. Scale bar = 500 μm. (b) Enlarged view of the spheroids. The numbers indicate the electrode number in a well of a multielectrode array (MEA) plate. Blank and filled arrowheads indicate the electrodes (#4 and #13, respectively) used for propagation velocity analysis. Scale bar = 100 μm. B) Representative histogram and raster plot acquired for the spheroid sample cultured 5 weeks in vitro (at 5 WIV). (a) The vertical axes represent the spike frequency (upper) and electrode numbers in a well of an MEA plate (lower). The horizontal axis represents the measurement duration. Arrows indicate the bursts analyzed at the time of firing onset. Blank and filled arrowheads corresponded to those shown in A and indicate the beginning point of the NB detected at each electrode. C) Dose-dependency effects of drugs on the propagation velocity in spheroid samples at 5 WIV. More than 30 bursts recorded for 10 min were analyzed for each sample. For 4-aminopyridine (4-AP) n = 4, for picrotoxin n = 3, for 6-cyano-7-nitroquinoxaline-2, 3-dione (CNQX) n = 3, for dimethyl sulfoxide (DMSO) n = 4. Data were expressed by means + standard errors. Statistical analyses were performed using ANOVA followed by post hoc Dunnet’s test, *p < 0.05, **p < 0.01, ***p < 0.001