Neural stem cells are adult stem cells but you also find them in embryos (already in "adult" differentiation status) and they have the potential to develop into neurons and glial cells. We recommend isolating them from rat and mouse embryos because more cells can be obtained from embryos than from adults. For Nucleofection of NSC from foetal or adult brains, you can use the same Optimized Protocol. Neuronal progenitor cells already have a neuronal phenotype but are not mature neurons yet. They have a lower differentiation potential than neural stem cells.