VeCell: A Fiji Plugin to unveil the spatio-temporal dynamics of macroglial cell development and proximity to blood vessels

Brain cortical development results from the proliferation, differentiation, migration and maturation of many cell types. While neuronal development is well characterized, the mechanisms regulating macroglial cells (oligodendrocytes and astrocytes) development remain largely unknown. Recent works suggest that the vascular system plays a key, yet under-evaluated role in this process. To investigate this, we developed VeCell, a Fiji plugin designed to analyse the spatial organization of macroglial cells relative to blood vessels. Using immunolabeling for Sry-box transcription factor (Sox) 9 (macroglial progenitors and astrocytes) and Sox10 (oligodendrocyte lineage), we determined macroglia density, distribution and proximity to blood vessels from postnatal day (P) 1 to P60 in the somatosensory cortex. We showed that Sox9+ cells were evenly distributed across cortical layers with regular intercellular spacing. In contrast, Sox10+ cells concentrated in deeper cortical layers, and exhibited a random distribution. Vascular density and branching increased markedly between P5 and P15 and macroglial cells were closer to blood vessels from P15 onward. As a proof of concept, we used Vecell to show that astrocyte cortical distribution is preserved in MLC1-deficient mice, a model of Megalencephalic leukoencephalopathy with subcortical cysts, in which astrocyte perivascular coverage is altered. Thus, VeCell is a powerful tool to characterize and quantify macroglial cell distribution in the brain and in relation to the vasculature. It revealed distinct distribution and postnatal development patterns for astrocytes and oligodendrocytes. Table of Contents EntryO_LIVeCell: quantification of macroglial cell density, distribution, and proximity to blood vessels C_LIO_LIFrom P5, Sox9 cells are evenly distributed, unlike Sox10 cells C_LIO_LIFrom P15, Sox9 cells are located closer to blood vessels than Sox10 cells C_LI O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/632893v2_ufig1.gif" ALT="Figure 1"> View larger version (52K): org.highwire.dtl.DTLVardef@e75f07org.highwire.dtl.DTLVardef@fdb99org.highwire.dtl.DTLVardef@11a1ef8org.highwire.dtl.DTLVardef@1e737a1_HPS_FORMAT_FIGEXP M_FIG C_FIG