(A) Immunofluorescence whole brain coronal section images of IBA1+ cells (green) show the Stages (i.e. sequential time course), including the symmetrical distribution and expansion, of the ‘wave’ of repopulating myeloid cells that fill the brain during WM repopulation. White lines separate different brain regions: corpus callosum (CC), cortex (CTX), caudoputamen (CP), and lateral ventricle (LV). White dotted lines and yellow arrows indicate the edge and direction of the ‘wave’, highlighting the radial migratory patterns of WM repopulating cells. Yellow dashed arrows indicate the direction of the tangential migratory pattern of WM repopulating cells, mostly utilizing WM tracts. (B) Representative tile scan confocal images of the migration of WM repopulating IBA1+ cells (green) out of the WM tracts and into cortical regions. White dotted lines indicate WM boundaries.