Dividing precursor cells of the embryonic cortical ventricular zone have morphological and molecular characteristics of radial glia.
The embryonic ventricular zone (VZ) of the cerebral cortex contains migrating neurons, radial glial cells, and a large population of cycling progenitor cells that generate newborn neurons. The latter two cell classes have been assumed for some time to be distinct in both function and anatomy, but the cellular anatomy of the progenitor cell type has remained poorly defined. Several recent reports have raised doubts about the distinction between radial glial and precursor cells by demonstrating that radial glial cells are themselves neuronal progenitor cells (Malatesta et al., 2000; Hartfuss et al., 2001; Miyata et al., 2001; Noctor et al., 2001). This discovery raises the possibility that radial glia and the population of VZ progenitor cells may be one anatomical and functional cell class. Such a hypothesis predicts that throughout neurogenesis almost all mitotically active VZ cells and a substantial percentage of VZ cells overall are radial glia. We have therefore used various anatomical, immunohistochemical, and electrophysiological techniques to test these predictions. Our data demonstrate that the majority of VZ cells, and nearly all mitotically active VZ cells during neurogenesis, both have radial glial morphology and express radial glial markers. In addition, intracellular dye filling of electrophysiologically characterized progenitor cells in the VZ demonstrates that these cells have the morphology of radial glia. Because the vast majority cycling cells in the cortical VZ have characteristics of radial glia, the radial glial precursor cell may be responsible for both the production of newborn neurons and the guidance of daughter neurons to their destinations in the developing cortex.
Noctor
Stephen C
SC
Department of Neurology, Columbia College of Physicians and Surgeons, New York, New York 10032, USA.
Flint
Alexander C
AC
Weissman
Tamily A
TA
Wong
Winston S
WS
Clinton
Brian K
BK
Kriegstein
Arnold R
AR
D000818:Animals; D000943:Antigens, Differentiation / Q000096:biosynthesis; D019470:Biolistics; D002454:Cell Differentiation / Q000502:physiology; D002455:Cell Division; D002540:Cerebral Cortex / Q000166:cytology* / Q000196:embryology*; D002552:Cerebral Ventricles / Q000166:cytology*; D005456:Fluorescent Dyes; D049452:Green Fluorescent Proteins; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D008164:Luminescent Proteins / Q000096:biosynthesis / Q000235:genetics; D008863:Microspheres; D008938:Mitosis; D009457:Neuroglia / Q000166:cytology*; D018408:Patch-Clamp Techniques; D017966:Pyramidal Cells / Q000166:cytology / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012190:Retroviridae / Q000235:genetics; D016196:S Phase; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism; D014746:Vimentin / Q000096:biosynthesis
D000943:Antigens, Differentiation; D005456:Fluorescent Dyes; D008164:Luminescent Proteins; D014746:Vimentin; D049452:Green Fluorescent Proteins