Intermediate Neuronal Progenitors (Basal Progenitors) Produce Pyramidal–Projection Neurons for All Layers of Cerebral Cortex
Open Access
- 23 January 2009
- journal article
- research article
- Published by Oxford University Press (OUP) in Cerebral Cortex
- Vol. 19 (10), 2439-2450
- https://doi.org/10.1093/cercor/bhn260
Abstract
The developing cerebral cortex contains apical and basal types of neurogenic progenitor cells. Here, we investigated the cellular properties and neurogenic output of basal progenitors, also called intermediate neuronal progenitors (INPs). We found that basal mitoses expressing transcription factor Tbr2 (an INP marker) were present throughout corticogenesis, from embryonic day 10.5 through birth. Postnatally, Tbr2+ progenitors were present in the dentate gyrus, subventricular zone (SVZ), and posterior periventricle (pPV). Two morphological subtypes of INPs were distinguished in the embryonic cortex, “short radial” in the ventricular zone (VZ) and multipolar in the SVZ, probably corresponding to molecularly defined INP subtypes. Unexpectedly, many short radial INPs appeared to contact the apical (ventricular) surface and some divided there. Time-lapse video microscopy suggested that apical INP divisions produced daughter INPs. Analysis of neurogenic divisions (Tis21-green fluorescent protein [GFP]+) indicated that INPs may produce the majority of projection neurons for preplate, deep, and superficial layers. Conversely, proliferative INP divisions (Tis21-GFP−) increased from early to middle corticogenesis, concomitant with SVZ growth. Our findings support the hypothesis that regulated amplification of INPs may be an important factor controlling the balance of neurogenesis among different cortical layers.Keywords
This publication has 63 references indexed in Scilit:
- Tbr2 Directs Conversion of Radial Glia into Basal Precursors and Guides Neuronal Amplification by Indirect Neurogenesis in the Developing NeocortexNeuron, 2008
- The T-box transcription factor Eomes/Tbr2 regulates neurogenesis in the cortical subventricular zoneGenes & Development, 2008
- Live Imaging at the Onset of Cortical Neurogenesis Reveals Differential Appearance of the Neuronal Phenotype in Apical versus Basal Progenitor ProgenyPLOS ONE, 2008
- Oscillations in Notch Signaling Regulate Maintenance of Neural ProgenitorsNeuron, 2008
- Characterization of the proneural gene regulatory network during mouse telencephalon developmentBMC Biology, 2008
- Distinct behaviors of neural stem and progenitor cells underlie cortical neurogenesisJournal of Comparative Neurology, 2008
- A Molecular Neuroanatomical Study of the Developing Human Neocortex from 8 to 17 Postconceptional Weeks Revealing the Early Differentiation of the Subplate and Subventricular ZoneCerebral Cortex, 2007
- Differential Notch signalling distinguishes neural stem cells from intermediate progenitorsNature, 2007
- Eomes::GFP—a tool for live imaging cells of the trophoblast, primitive streak, and telencephalon in the mouse embryogenesis, 2007
- A novel immunohistochemical method to estimate cell‐cycle phase distribution in archival tissue: implications for the prediction of outcome in colorectal cancerThe Journal of Pathology, 2003