We found that the growth of the somatic area of the hiPSC-derived NPCs followed an increasing and then decreasing pattern, in which the soma area increased significantly to day 12 and then plateaued. The growth of neurites followed a similar pattern, with the number of the primary, secondary, and tertiary branches peaking at differentiation day 3 to day 9 and the length of axons and dendrites peaking at differentiation day 9. The growth cone is the key factor of the guidance and motility of axonal growth in the early stage of differentiation and neuron regeneration28. Our study found that growth cones also showed a pattern of rapid growth up to differentiation day 9, followed by a significantly decrease. The bundled F-actin in blunt and filopodia growth cone transport cargo both anterogradely and retrogradely. In contrast, F-actin in the lamellipodium growth cone forms a dendritic network through the action of dendritic nucleator proteins and capping proteins. It is not surprising that the growth pattern of the growth cone coincides with that of the dendrites and the axon. Overall, morphologically, the growth
