Role of Intermediate Progenitor Cells in Cerebral Cortex DevelopmentPontious A. · Kowalczyk T. · Englund C. · Hevner R.F.
Department of Pathology, University of Washington, Seattle, Wash., USA
Intermediate progenitor cells (IPCs) are a type of neurogenic transient amplifying cells in the developing cerebral cortex. IPCs divide symmetrically at basal (abventricular) positions in the neuroepithelium to produce pairs of new neurons or, in amplifying divisions, pairs of new IPCs. In contrast, radial unit progenitors (neuroepithelial cells and radial glia) divide at the apical (ventricular) surface and produce only single neurons or single IPCs by asymmetric division, or self-amplify by symmetric division. Histologically, IPCs are most prominent during the middle and late stages of neurogenesis, when they accumulate in the subventricular zone, a progenitor compartment linked to the genesis of upper neocortical layers (II–IV). Nevertheless, IPCs are present throughout cortical neurogenesis and produce neurons for all layers. In mice, changes in the abundance of IPCs caused by mutations of Pax6, Ngn2, Id4 and other genes are associated with parallel changes in cortical thickness but not surface area. In gyrencephalic brains, IPCs may play broader roles in determining not only laminar thickness, but also cortical surface area and gyral patterns. We propose that regulation of IPC genesis and amplification across developmental stages and regional subdivisions modulates laminar neurogenesis and contributes to the cytoarchitectonic differentiation of cortical areas.
© 2008 S. Karger AG, Basel
Received: January 29, 2007
Accepted after revision: April 4, 2007
Number of Print Pages : 9
Number of Figures : 2, Number of Tables : 2, Number of References : 72
Vol. 30, No. 1-3, Year 2008 (Cover Date: December 2007)
Journal Editor: Campagnoni, A.T. (Los Angeles, Calif.)
ISSN: 0378–5866 (print), 1421–9859 (Online)
For additional information: http://www.karger.com/DNE