William D Richardson

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Platelet-derived growth factor α receptor (PDGFRA)/NG2–expressing glia are distributed throughout the adult CNS. They are descended from oligodendrocyte precursors (OLPs) in the perinatal CNS, but it is not clear whether they continue to generate myelinating oligodendrocytes or other differentiated cells during normal adult life. We followed the fates of(More)
The developmental origin of oligodendrocyte progenitors (OLPs) in the forebrain has been controversial. We now show, by Cre-lox fate mapping in transgenic mice, that the first OLPs originate in the medial ganglionic eminence (MGE) and anterior entopeduncular area (AEP) in the ventral forebrain. From there, they populate the entire embryonic telencephalon(More)
Oligodendrocyte precursors (OPs) continue to proliferate and generate myelinating oligodendrocytes (OLs) well into adulthood. It is not known whether adult-born OLs ensheath previously unmyelinated axons or remodel existing myelin. We quantified OP division and OL production in different regions of the adult mouse CNS including the 4-month-old optic nerve,(More)
We determined the embryonic origins of adult forebrain subventricular zone (SVZ) stem cells by Cre-lox fate mapping in transgenic mice. We found that all parts of the telencephalic neuroepithelium, including the medial ganglionic eminence and lateral ganglionic eminence (LGE) and the cerebral cortex, contribute multipotent, self-renewing stem cells to the(More)
After central nervous system (CNS) demyelination-such as occurs during multiple sclerosis-there is often spontaneous regeneration of myelin sheaths, mainly by oligodendrocytes but also by Schwann cells. The origins of the remyelinating cells have not previously been established. We have used Cre-lox fate mapping in transgenic mice to show that(More)
Oligodendrocyte progenitors originate near the floor plate of the spinal cord, then proliferate and migrate throughout the cord before giving rise to oligodendrocytes. Progenitor cell proliferation stops before birth because the cell cycle slows down, linked to an increase in differentiation and death. Experiments with transgenic mice show that(More)
The neck and shoulder region of vertebrates has undergone a complex evolutionary history. To identify its underlying mechanisms we map the destinations of embryonic neural crest and mesodermal stem cells using Cre-recombinase-mediated transgenesis. The single-cell resolution of this genetic labelling reveals cryptic cell boundaries traversing the seemingly(More)
Oligodendrocyte precursors first arise in a restricted ventral part of the embryonic spinal cord and migrate laterally and dorsally from there. Later, secondary sources develop in the dorsal cord. Normally, the ventrally-derived precursors compete with and suppress their dorsal counterparts. There are also ventral and dorsal sources in the forebrain, but(More)
Cycling glial precursors-"NG2-glia"-are abundant in the developing and mature central nervous system (CNS). During development, they generate oligodendrocytes. In culture, they can revert to a multipotent state, suggesting that they might have latent stem cell potential that could be harnessed to treat neurodegenerative disease. This hope has been subdued(More)
To design therapies for demyelinating diseases such as multiple sclerosis, it will be important to understand the mechanisms that control oligodendrocyte progenitor cell (OPC) numbers in the adult central nervous system (CNS). During development, OPC numbers are limited by the supply of platelet-derived growth factor-A (PDGF-A). Here, we examine the role of(More)