The field of cellular reprogramming has the potential open avenues for disease modeling and personalized medicine. Many protocols have been developed to differentiate embryonic stem cells or induced pluripotent stem cells into neurons, but a simple and efficient method for creating matured neurons is desired. This research was testing high levels of potassium in cell culture medium for promoting neural differentiation while maintaining cell survival. We hypothesized that a high extracellular level of potassium will facilitate differentiation of neural stem cells. The neural stem cells were induced by treating mouse embryonic fibroblasts (MEFs) with chemical compounds. Immunocytochemistry results suggested reprogramming of MEFs into multiple cells of the neural lineage. Immunoreactivity of Sox2 and Nestin was seen in these cells, suggesting neural stem cell character. Some cells also showed MAP2, NeuN, and Tuj-1 which are markers of relatively matured neurons. GFAP, an astrocytic glia marker, was also found in some cells. There was no detectable effect of high extracellular potassium on promoting neural process outgrowth. We anticipated that the cells in a higher concentration of potassium would show a higher expression of those neural markers; however, such a change was not observed. High extracellular potassium alone does not promote neural differentiation in these cells.
