Polarized neocortical organoids with areal signatures upon the formation of anterior and posterior organizers. [Spatial Transcriptomics]

Most methods to generate neocortical organoids from human pluripotent stem cells lack clear evidence for anterior and posterior polarization, which eventually parcellate into different areal identities with unique cytoarchitecture, cell composition, connectivity, and gene expression patterns in vivo. This study demonstrates the polarization of neocortical organoids. By adding rostral (FGF8) and caudal (BMP4/WNT agonists) morphogens, neocortical organoids upregulate and downregulate anterior or posterior homeodomain transcription factors, including SP8 and COUPTF1. With the application of FGF8 or BMP4/WNT agonists, the formation of anterior or posterior organizers was observed in neocortical organoids. Single-cell RNA-sequencing analyses exhibited molecular signatures associated with different lobes/areas found in multiple studies using human fetal tissue.