Human embryonic stem cells (hESC) and induced pluripotent stem cells (hiPSC) possess the capability of differentiating into all derivatives of the three germ layers including neural cells. Human pluripotent stem cell (hPSC) derived neural cells have been used for studying nervous system development, modeling neurologic disorders, neurotoxicology and drug screening. SMAD signaling plays a crucial role in neural induction. Dual inhibition of SMAD signaling by Noggin and SB431542 is sufficient to induce rapid and complete neural conversion of hPSCs [1]. In 2010, Wenlin Li and colleagues found that synergistic inhibition of glycogen synthase kinase 3 (GSK3) and transforming growth factor β (TGF-β) could efficiently differentiate hPSCs to homogenous neural epithelium in 7 days [2]. The derived neural stem cells (NSCs) can self-renew in the presence of human leukemia inhibitory factor (LIF) and inhibitors of GSK3 and TGF-β. NSCs possess the multipotential of differentiating into various neuronal and glial subtypes upon induction with specific patterning cues [2].

Based on the advances in neural differentiation methodologies, we developed hPSC Neural Induction Medium (PSCNIM, Cat. #5931), a serum-free medium, to efficiently convert hPSCs to NSCs under adherent culture conditions. The hPSCs are converted to homogenous neural epithelium using neural induction medium (Figure 1). After a 7 – 10 day treatment with PSCNIM, more than 90% of cells expressed the neural stem cell markers: Nestin and Sox2; while the pluripotency marker Nanog expression was lost (Figure 2). NSCs derived from hPSC can be maintained in the induction medium for at least 5 passages (~24 days), can efficiently form rosettes (Figure 3) and be expanded as neural progenitor cells in EGF and FGF containing medium, or differentiated into neural lineages such as neurons and astrocytes (Figure 3).