NMDAR-mediated transcriptional control of gene expression during the development of medial ganglionic eminence-derived interneurons

Medial ganglionic eminence (MGE)-derived parvalbumin (PV)+, somatostatin (SST)+, and Neurogliaform (NGFC)-type cortical and hippocampal interneurons, have distinct molecular, anatomical and physiological properties. However, the molecular mechanisms regulating their diversity remain poorly understood. Here, via single-cell transcriptomics, we show that the obligate NMDA-type glutamate receptor (NMDAR) subunit gene Grin1 mediates subtype-specific transcriptional regulation of gene expression in MGE-derived interneurons, leading to altered subtype identities. Notably, MGE-specific conditional Grin1 loss results in a systemic downregulation of diverse transcriptional, synaptogenic, and membrane excitability regulatory programs. These widespread gene expression abnormalities mirror aberrations that are typically associated with neurodevelopmental disorders, particularly schizophrenia. Our study hence provides a roadmap for the systematic examination of NMDAR signaling in interneuron subtypes, revealing potential MGE-specific genetic targets that could instruct future therapies of psychiatric disorders.