Adventures in Wonderland

For the last several decades, there has been little debate over the origins of central and peripheral glia. Central nervous system (CNS) glia, including oligodendrocytes, astrocytes, and radial glia, are specified from CNS neural precursors[1], whereas peripheral nervous system (PNS) glia, including Schwann cells and satellite glia, are derivatives of the neural crest [2]. However, this strict delineation of central versus peripheral glia is being challenged, and the implications could revolutionize human medicine. In the February issue of PLOS Genetics, Weider and colleagues report that a cell population with characteristics very similar to CNS oligodendrocytes can arise from satellite glia in the periphery with only the overexpression of a single transcription factor [3]. This work, in conjunction with several other recent papers [4–7], has us not only peering through Alice’s looking glass but also crossing straight through.