Generation of Otic Lineages from Integration-Free Human-Induced Pluripotent Stem Cells Reprogrammed by mRNAs

Figure 2

(a) Diagram showing the protocol for the generation of spiral ganglion-like neurons. (b) qPCR showing relative expression levels of NEUROG and NEUROD. Data shown as fold change against undifferentiated cells from the same initial population. (c) ONPs differentiating into neurons express markers such as TUJ1 and POU4F1, scale bar is 200 μm. Immunofluorescence images shown are from cell line FF5. (d) Electrophysiological properties of differentiating neuronal-like cells. Depolarizing and hyperpolarizing voltage steps in 10 mV nominal increments from a holding potential of -84 mV revealed Na⁺ currents (; (d), expanded in (e)) in 3 out of 3 neuronal-like cells, small outward K⁺ currents (; (d)) in 3 out of 3 cells and a small inward K⁺ current () in 1 out of 3 cells (d). The peak - curve for indicates that activated at potentials near -40 mV and reached a maximum size of pA near -10 mV (; (f)). The steady state - curve for was also generated from a holding potential of -84 mV, and the current size at 0 mV and measured at 160 ms was pA, (g). The small inward K⁺ current () was evident for membrane potentials negative to -80 mV (g).

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