library_construction_protocol: (Post-mortem samples) Nuclei were isolated from frozen surgical resection specimen as described previously (Al- Dalahmah et al., 2020). Briefly, frozen tissue samples were homogenized using a dounce homogenizer in ice-cold 30% sucrose 0.1% Triton-X 100 based homogenization buffer. 10-15 strokes of the loose dounce pestle were followed by 10-15 strokes of the tight dounce pestle on ice. Mixing using a P1000 pipette followed before filtration through a BD Falcon 40um filters. Filtration was repeated after a 10-minute spin at 1000g at 4c. A cleanup step followed using a density gradient step as described (Krishnaswami et al., 2016) For neuronal differentiation of NPCs, expansion media was changed 2 days after splitting to neuronal induction media consisting of N2B27 medium supplemented with 1 μM PMA, 200 μM AA and 3 μM CHIR 99021. After 6 days of differentiation the neuronal induction media was replaced by neuronal maturation media consisting of N2B27 with 20 ng/ml BDNF, 10 ng/ml GDNF, 1 ng/ml TGF-β3 (Peprotech), 200 μM AA, and 500 μM dbcAMP (Sigma Aldrich). Media was changed every other day and cultures were analyzed after three weeks in maturation conditions. (Post-mortem samples) The nuclear pellet was suspended in 1% BSA in PBS resuspension buffer containing RNAse inhibitors. A final filteration step using 20um Flowmi TM filters followed before dilution to 700-1200 nuclei per ul in resuspension buffer. The nuclear suspensions were processed by the Chromium Controller (10x Genomics) using single Cell 3' Reagent Kit v2 or v3 (Chromium Single Cell 3' Library & Gel Bead  Kit v2, catalog number: 120237; Chromium Single Cell A Chip Kit, 48 runs, catalog number: 120236; 10x Genomics). Grafts composed of human iPSC-derived neural cells were microdissected and submitted to nuclei isolation, followed by a standard single nucleus RNA-seq library preparation and sequencing. snRNA (single-nuclei RNA sequencing)