(black cells with nuclei shown in yellow) born in the adult subventricular zone (SVZ) migrate in chains through the rostral migratory stream (RMS) to the olfactory bulbs (OB). The RMS contains blood vessels (red bars) oriented parallel with the path of migration which neuroblasts can use as a scaffold to enhance migration. Also, astrocytes (blue) have been found within the RMS where they exhibit a polar morphology with processes oriented parallel to the path of migration. The RMS is also surrounded by astrocyte endfeet (blue bars) which create a mostly enclosed tube around neuroblasts as they migrate through extracellular matrix (diagonal light grey bars). Additionally, cell-bound and soluble factors influence migration efficacy including chemorepulsive cues that repel neuroblasts from the SVZ and from areas surrounding the RMS (red arrows) and chemoattractive cues that promote migration towards the OB (green arrows), many of which exist in gradients across the RMS (color intensity changes).
