Human stem cell-derived GABAergic interneuron development reveals early emergence of subtype diversity followed by gradual electrochemical maturation [snRNA-seq]

Medial ganglionic eminence-derived inhibitory GABAergic pallial interneurons (MGE-pINs) are essential for cortical development and function. Dysfunction in MGE-pINs is associated with numerous neurological disorders. We developed a human MGE-pIN cell therapy candidate from pluripotent stem cells, which is undergoing clinical trial evaluation for drug-resistant epilepsy (NCT05135091). Here, we performed single nuclei RNA sequencing and analyzed the transcriptomes of xenografted hMGE-pINs over the lifespan of host mice. Comparative transcriptomic analyses with published human brain datasets revealed that over 97% of grafted human cells developed into pallial MGE-derived somatostatin (SST) and parvalbumin (PVALB) subtypes, including populations that exhibit selective vulnerability in Alzheimer’s disease. Transplanted hMGE-pINs progressed through distinct transcriptional states sequentially involving neuronal migration, synapse organization, and the maturation of electrophysiological properties, demonstrating a surprisingly rapid emergence of subclass-specific features within weeks after grafting. We present molecular, electrophysiological, and morphological data that collectively confirm the derivation of diverse bona-fide human SST and PVALB subtypes, providing a high-fidelity model to study human MGE-pIN development and functional maturation in both healthy and diseased states as well as a compositional atlas for regenerative cell therapy applications.