Fig. 3

Common ways to generate human neural cells for modeling Alzheimer’s disease. Somatic cells may either be directly converted into induced neuronal (iN) cells (transdifferentiation) or reprogramed into iPSCs. Neural induction – mainly by dual-smad inhibition – yields NPCs, which can further be differentiated into neuron and astrocytes, either pure or of mixed-types. Alternatively, iPSCs can be directly converted to neurons (also called iN cell in this case) by forced expression of transcription factors such as neurogenin2, omitting the NPC step. Microglial cells can be obtained by iPSC differentiation into erythromyeloid progenitors (EMPs) which are further differentiated to microglia. However, few alternative protocols achieve microglial differentiation via NPCs