Article

In vivo time-lapse imaging shows dynamic oligodendrocyte progenitor behavior during zebrafish development

Department of Biological Sciences, Vanderbilt University, 465 21st Avenue South, Nashville, Tennessee 37232, USA.
Nature Neuroscience (Impact Factor: 14.98). 01/2007; 9(12):1506-11. DOI: 10.1038/nn1803
Source: PubMed

ABSTRACT Myelinating oligodendrocytes arise from migratory and proliferative oligodendrocyte progenitor cells (OPCs). Complete myelination requires that oligodendrocytes be uniformly distributed and form numerous, periodically spaced membrane sheaths along the entire length of target axons. Mechanisms that determine spacing of oligodendrocytes and their myelinating processes are not known. Using in vivo time-lapse confocal microscopy, we show that zebrafish OPCs continuously extend and retract numerous filopodium-like processes as they migrate and settle into their final positions. Process remodeling and migration paths are highly variable and seem to be influenced by contact with neighboring OPCs. After laser ablation of oligodendrocyte-lineage cells, nearby OPCs divide more frequently, orient processes toward the ablated cells and migrate to fill the unoccupied space. Thus, process activity before axon wrapping might serve as a surveillance mechanism by which OPCs determine the presence or absence of nearby oligodendrocyte-lineage cells, facilitating uniform spacing of oligodendrocytes and complete myelination.

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