Evidence for a second wave of oligodendrogenesis in the postnatal cerebral cortex of the mouse.
The existing view is that cortical oligodendrocytes (OLs) in rodents are born from the cortical subventricular zone (SVZ) after birth, but recent data suggest that many forebrain oligodendrocyte progenitor cells (OPCs) are specified much earlier (between E9.5 and E13.5 in the mouse) in the ventricular zone of the ventral forebrain under the control of sonic hedgehog (Shh) and migrate into the cortex afterward. We examined expression of specific early OL markers (PDGFRalpha, PLP/DM20, Olig2, and NG2) in the developing forebrain to clarify this issue. We propose that OPCs colonize the developing cortex in two temporally distinct waves. The gray matter is at least partially populated by a first wave of OPCs that arises in the medial ganglionic eminence and the entopeduncular area and spreads into the cortex via the developing cortical plate. The cerebral cortex benefits from the second wave of OPCs coming from residential SVZ. In the second wave, there might be two different types of precursor cells: PLP/DM20(+) cells populating only inner layers and PDGFRalpha(+) cells, which might eventually myelinate the outer regions as well.
Ivanova
Anna
A
Laboratory of Neural Information, National Institute for Physiological Sciences, Okazaki National Research Institutes, Aichi, Japan.
Nakahira
Eiko
E
Kagawa
Tetsushi
T
Oba
Akio
A
Wada
Tamaki
T
Takebayashi
Hirohide
H
Spassky
Nathalie
N
Levine
Joel
J
Zalc
Bernard
B
Ikenaka
Kazuhiro
K
D000818:Animals; D000831:Animals, Newborn; D000941:Antigens / Q000096:biosynthesis; D051792:Basic Helix-Loop-Helix Proteins; D002454:Cell Differentiation / Q000502:physiology*; D019070:Cell Lineage; D002540:Cerebral Cortex / Q000166:cytology / Q000196:embryology* / Q000254:growth & development*; D004622:Embryo, Mammalian; D005455:Fluorescent Antibody Technique; D017403:In Situ Hybridization; D051379:Mice; D008813:Mice, Inbred ICR; D018991:Myelin Proteolipid Protein / Q000096:biosynthesis; D009419:Nerve Tissue Proteins / Q000096:biosynthesis; D000076104:Oligodendrocyte Transcription Factor 2; D009836:Oligodendroglia / Q000166:cytology / Q000502:physiology*; D010982:Platelet-Derived Growth Factor / Q000096:biosynthesis; D011509:Proteoglycans / Q000096:biosynthesis; D013234:Stem Cells / Q000502:physiology*; D000099216:Chondroitin Sulfate Proteoglycan 4
D000941:Antigens; D051792:Basic Helix-Loop-Helix Proteins; D018991:Myelin Proteolipid Protein; D009419:Nerve Tissue Proteins; D000076104:Oligodendrocyte Transcription Factor 2; D010982:Platelet-Derived Growth Factor; D011509:Proteoglycans; D000099216:Chondroitin Sulfate Proteoglycan 4; C512773:Olig2 protein, mouse; C075278:platelet-derived growth factor A