A common neural progenitor for the CNS and PNS

Cultured spinal cord neuroepithelial (NEP) cells can differentiate into neurons, oligodendrocytes and astrocytes and are morphologically and antigenically distinct from neural crest stem cells (NCSCs) that generate the PNS. NEP cells, however, can generate p75/nestin-immunoreactive cells that are morphologically and antigenically similar to previously characterized NCSCs. NEP-derived p75-immunoreactive cells differentiate into peripheral neurons, smooth muscle, and Schwann cells in mass and clonal culture. Clonal analysis of NEP cells demonstrates that a common NEP progenitor cell generated both CNS and PNS phenotypes. Differentiation into NCSCs was promoted by BMP-2/4 and differentiation did not require cells to divide, indicating that BMP played an instructive role in the differentiation process. Thus, individual NEP cells are multipotent and can differentiate into most major types of cell in the CNS and PNS and that PNS differentiation involves a transition from a NEP stem to another more limited, p75-immunoreactive, neural crest stem cell.