ENHANCING DENDRITIC SPINE FORMATION AND FUNCTIONAL MATURATION IN IPSC-DERIVED NEURONS USING AN ALTERNATIVE TRANSCRIPTION FACTOR

The study of psychiatric diseases using iPSC-derived neurons is of major importance, as it enables translational research in human-relevant cellular models. Most current studies rely on the overexpression of Neurogenin-2 (NEUROG2) to generate glutamatergic neurons; however, several limitations remain, including culture heterogeneity, limited dendritic spine formation, and structural and functional immaturity. In addition, the majority of these studies are performed in two-dimensional (2D) cultures, despite the fact that the brain is a three-dimensional (3D) structure, where the spatial organization plays a crucial role in network complexity and dendritic spine development. In this study, we introduce an alternative transcription factor, TF-X, aimed at improving neuronal maturation and suitability for disease modeling in 2D and 3D neuronal structures. Human TF-X-derived neurons were imaged for 6 months using two-photon laser scanning microscopy to assess dendritic morphology and spine formation. Whole-cell patch-clamp recordings were performed to evaluate single-cell electrophysiological properties. TF-X-derived neurons formed a homogeneous neuronal population and, compared to NEUROG2-derived neurons, exhibited increased dendritic spine density, thicker dendrites, and enhanced electrophysiological maturity. These findings demonstrate that TF-X enables the generation of neurons with improved structural and functional properties relevant to synaptic pathology, providing a robust platform for studying dendritic spine and synaptic transmission deficits associated with psychiatric diseases and for advancing human-relevant disease modeling and therapeutic development.