In schizophrenia organoids, FGFR1 expression in the CZ was greatly reduced, as compared to control iPSC organoids at 2 weeks (Fig. 5a; Supplementary Fig. 4, a4 and a5), as well as at 5 weeks (Fig. 5b, Supplementary Fig. 4b and c). Few or no FGFR1-expressing cells were detected in the cortex of the schizophrenia organoids in investigated iPSC lines. In three patients and three controls, using multiple sections and ROIs, we counted the percent of DAPI-stained nuclei that were positive for nFGFR1. The number of nFGFR1-expressing cells was reduced from 37% in control organoids to 6.9% in the schizophrenia organoids (p < 0.0001) (Fig. 5c; Supplementary Fig. 5d).
