Figure 2.

SVZ-derived migratory cells are neuroblasts and associate with perivascular astrocytic end feet. A, GAD65-GFP positive cell (green) with a leading process wrapping around a capillary (red) in the granule cell layer of the young adult olfactory bulb. B, CTG-labeled SVZ-derived progenitor (green) migrating along a bulb blood vessel (lumen tetramethylrhodamine isothiocyanate fill; red) with GFAP immunohistochemical labeling of astrocytes (blue). GFAP-positive processes are rarely seen between the migratory cell and vessel and no CTG-positive cells express GFAP. C, Bright-field photograph showing DAB-stained CTb-labeled SVZ-derived progenitors (arrows). CTb in cell processes is typically punctate because of lissome accumulation of the CTb. D, Electron microscopic image of the same field shown in C showing the perivascular space around the blood vessel (BV). Endothelial cells have been pseudocolored red, perivascular astrocyte processes blue, and the migrating SVZ progenitors green. Punctate DAB reaction product is present in lysosomes and around a migrating cell nucleus (arrows) at identical locations to that present in the bright-field photograph in C. E, Higher magnification photograph showing a thin astrocyte process (a) between the migrating (m) and the endothelial cell (e). A small space containing the ECM is present between the astrocyte and migratory cell. Scale bar: (in E) A, B, 10 μm; C, 3 μm; D, 2 μm; E, 250 nm.