Direct Reprogramming of Mouse Fibroblasts to Neural Stem Cells by Small Molecules

Figure 3

Mature neurons from SMINS-TTF-3 cells. (a) SMINS-TTF-3 cells were cultured in mature neural medium for one month and stained by mature neuron markers VAMP2 (green) and NeuN (Red). (b) Electrophysiological investigations of a subset of long-term differentiated cells showed the presence of both inward Na⁺ currents and outward K⁺ currents in response to electrical stimulation with steps from −70 to +70 mV (10 mV increments) from a holding potential of −80 mV. Representative trace with 100 ms steps, inset with 20 ms steps (inset scale bars represent 5 ms on -axis, 10 nA on -axis). (c) Mean ± SEM maximal Na⁺ (closed circles) and K⁺ currents (open circles, ). (d) These cells demonstrated action potential firing in response to current injection ((i) 20 pA for 5 s, (ii) and (iii) 50 pA for 5 s) or spontaneously (iv). Scale bar: 10 μm (a).

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