Whither Stem Cell Biology?

Accessible online at: www.karger.com/journals/dne In the best of worlds, the clinician of the future will be able to repair an injury to the CNS with an armamentarium of therapies. Undoubtedly, included in this will be ‘magic bullets’ to replace lost cells in specific and functionally constructive ways. The key to finding such therapies may lie in the burgeoning field of stem cell biology. Stem cell research has dramatically increased over the last few years. In recent years, stem cells and their close kin ‘progenitor cells’ and ‘precursor cells’, all of which have long been of interest to developmental neurobiologists, have captured the attention of a larger contingent of neuroscientists because of their expected therapeutic potential. In the future, for example, it is hoped (and indeed planned by some) that neural stem cells will be harvested, expanded in vitro and used for heterologous or homologous transplantation to treat injuries or cure degenerative diseases of the CNS. Alternatively, genetically engineered stem cells could be used to correct neurological diseases caused by genetic mutations. Perhaps the most challenging, but most attractive exploitation of stem cells would be to learn how to re-activate latent stem cells in the adult brain to effect repair and regeneration of damaged or degenerated circuits. It has long been known that neurogenesis continues in discrete and particular areas of the adult mammalian brain. Recent demonstrations that multipotential progenitors can be propagated and differentiated in vitro have catalyzed the recent revival in CNS stem/progenitor cell research. Anticipating that research on neural stem cells is a growing discipline (pun intended!) and that development and regeneration are presumably closely related, the editors of Developmental Neuroscience solicited articles for this Special Issue on ‘Stem Cells and Progenitors’ to advance our understanding of the cellular and molecular properties of the germinal matrices of the CNS, and the stem cells and progenitors they harbor. Of special interest were original articles that added to our knowledge of the progenitors in the forebrain ventricular and subventricular zones. The goal was to publish a volume containing high-quality enduring articles, that would highlight established or emerging areas of stem/progenitor cell research. The editors’ and publisher’s goal was to draw attention to this relatively immature field of study. Despite the fact that new findings in this field garner the attention of the popular media and that review articles appear almost monthly in neuroscience journals, the topic is still timely. Importantly, no single journal has yet emerged as the vehicle for publishing studies on CNS stem cells and progenitors. Beginning with this special issue, Developmental Neuroscience is uniquely poised to become that vehicle, and we hope that Developmental Neuroscience becomes a destination for articles reporting important revelations about neural stem cells and progenitors. Figure 1 shows a simplistic diagram of the stem/progenitor cells in the germinal matrices of the forebrain. It depicts the two chief germinal zones of the brain, the ventricular zone (VZ) and the subventricular zone (SVZ). As shown, cells in the VZ are radially oriented, whereas SVZ cells are tangentially oriented with reference to the ventricle. In addition, it depicts the interkinetic movement of the nuclei of VZ cells, which is not characteristic