Myelination is one of the last events during mammalian brain development and is thought to continue into young adulthood in humans. Even in adulthood, ongoing low-level myelination is essential for neural homeostasis, and for dynamic processes such as learning and memory. Deficits in myelination resulting in abnormal white matter and disruption of neuronal function are observed in a wide variety of disorders of the CNS. One strategy for alleviating these deficits is to enhance the genesis of myelin-forming oligodendrocytes from their upstream precursor parents, oligodendrocyte precursor cells (OPCs). However, the capability of these OPCs to contribute to remyelination in injury or disease in the adult CNS remains unclear.  To better understand adult oligodendrogenesis and remyelination, our guests today characterized and compared murine OPCs during early postnatal myelination with those from adult injury-induced adult remyelination. Their findings identify two developing OPC groups subserving distinct postnatal functions and suggest that neonatal and adult OPC-mediated oligodendrogenesis are fundamentally different, The findings have important implications for therapeutic interventions aimed at myelin repair. GuestsFreda Miller, PhD, Michael Smith Laboratories, The University of British Columbia Beatrix Wang, BSC, PhD candidate, The University of British Columbia and The University of Toronto Supporting ContentSingle-cell approaches define two groups of mammalian oligodendrocyte precursor cells and their evolution over developmental time, Stem Cell ReportsAbout Stem Cell ReportsStem Cell Reports  is the open access, peer-reviewed journal of the International Society for Stem Cell Research communicating basic discoveries in stem cell research, in addition to translational and clinical studies. Stem Cell Reports  focuses on original research with conceptual or practical advances that are of broad interest to stem cell biologists and clinicians. X: @StemCellReportsAbout ISSCRWith nearly 5,000 members from 75+ countries, the International Society for Stem Cell Research (@ISSCR) is the preeminent global, cross-disciplinary, science-based organization dedicated to stem cell research and its translation to the clinic. The ISSCR mission is to promote excellence in stem cell science and applications to human health.ISSCR StaffKeith Alm, Chief Executive OfficerYvonne Fisher, Managing Editor, Stem Cell ReportsKym Kilbourne, Director of Media and Strategic CommunicationsJack Mosher, Scientific AdvisorVoice WorkBen Snitkoff