Human pluripotent stem cells (hPSC’s) can be used to generate a wide variety of somatic cell types. In addition, they can be grown in large numbers and thus can be a tractable source for cell types that are otherwise difficult to access—and notable amongst these are neurons. In principle, differentiation protocols can be developed to generate diverse types of neurons such as motor neurons, cortical neurons, etc.,. These capabilities can be used to enhance and augment discovery efforts in neuronal research and thus represent a significant addition to the neurobiologist’s tool kit.
The Rubin lab has developed protocols (see Rigamonti et al) that generate distinct neuronal subtypes with a high degree of reproducibility. Moreover, these cells are biologically and electrically competent as they can form synaptic connections and demonstrate spontaneous and stimulated electrical responsivity. Neuronal cell functionality has also been tested in gene expression studies and they faithfully reproduce the anticipated changes post depolarization. The cells also retain aspects of functional organization as evidenced by three dimensional marker gene expression in spheres. Long term viability (>4 months) and scale (billions of cells/flask) are additional pragmatic features that enable novel discoveries. Screening chemical libraries to identify compounds that overcome neuronal pathology is one notable example of an application of this technology.