Ultrastructural characterization of human oligodendrocytes and their progenitor cells by pre-embedding immunogold.

Oligodendrocytes are the myelinating cells of the central nervous system. They provide trophic, metabolic, and structural support to neurons. In several pathologies such as multiple sclerosis (MS), these cells are severely affected and fail to remyelinate, thereby leading to neuronal death. The gold standard for studying remyelination is the g-ratio, which is measured by means of transmission electron microscopy (TEM). Therefore, studying the fine structure of the oligodendrocyte population in the human brain at different stages through TEM is a key feature in this field of study. Here we study the ultrastructure of oligodendrocytes, its progenitors, and myelin in 10 samples of human white …

Wnt-Dependent Oligodendroglial-Endothelial Interactions Regulate White Matter Vascularization and Attenuate Injury

Recent studies have indicated oligodendroglial-vascular crosstalk during brain development, but the underlying mechanisms are incompletely understood. We report that oligodendrocyte precursor cells (OPCs) contact sprouting endothelial tip cells in mouse, ferret and human neonatal white matter. Using transgenic mice, we show that increased or decreased OPC density results in cognate changes in white matter vascular investment. Hypoxia promoted both increased OPC numbers and higher white matter vessel density, and endothelial cell expression of the Wnt pathway targets Apcdd1 and Axin2, suggesting paracrine OPC-endothelial signaling. Conditional knockout of OPC Wntless resulted in diminished w…

Tyramide Signal Amplification for Immunoelectron Microscopy