Fig. 2

iNSCs give rise to functional neurons, astrocytes, and oligodendrocytes. a Six weeks after differentiation, iNSC-derived neurons express markers of mature neurons such as MAP2 and NeuN. b–d Upon spontaneous differentiation, iNSCs give rise to vGLUT2-positive glutamatergic neurons (b). In addition, staining for GABA (c) or serotonin (5-HT, d) can be detected. e Peripherin⁺/BRN3A⁺/TUJ1⁺ PNS neurons in 30-day-differentiated iNSCs. Arrowhead highlights an example of a triple-positive cell. f–l Whole-cell current clamp measurements reveal the generation of multiple action potentials upon depolarizing current injections (f, n = 6/7). In response to depolarizing voltage steps, these neurons elicit fast and transient TTX-sensitive sodium-dependent inward currents and sustained 4-AP-sensitive potassium-dependent outward currents (g–i, n = 6/6). Spontaneous postsynaptic currents are observed in whole-cell voltage-clamp recordings, indicating the in vitro formation of functional excitatory (j, n = 6/7) and inhibitory (k, n = 1/8) synapses. Post-hoc immunostaining reveals co-localization of biocytin, TUJ1, and the human-specific marker hN in the recorded neurons (arrows, l). m–p iNSCs give rise to S100β⁺ (m) and GFAP⁺ (n) astrocytes as well as O4⁺ and OLIG2⁺ (o, p) oligodendrocytes. Scale bars: 50 μm