The ability to induce functional neurons via only transient transgene expression may be a critical proof-of-concept for those considering adapting this method for the modeling of neuropsychiatric disease. By eliminating the need for sustained overexpression of Ngn2 throughout neuronal induction, we believe we have reduced the likelihood that by employing induction strategies, rather than directed differentiation protocols, disease-related phenotypes or gene expression signatures unique to patient derived hiPSC neurons will be masked or obfuscated. Moreover, by combining induction with puromycin selection and Ara-C treatment, we have described a method that, with minimal optimization for cell density, can produce nearly pure populations of excitatory neurons from NPCs derived from independent hiPSC lines and different individuals.
