CELL AND MOLECULAR ANALYSIS OF THE DEVELOPING AND ADULT-MOUSE SUBVENTRICULAR ZONE OF THE CEREBRAL HEMISPHERES

The subventricular zone (SVZ) of the lateral ventricle remains mitotic ally active in the adult mammalian central nervous system (CNS). Recen t studies have suggested that this region may contain neuronal precurs ors (neural stem cells) in adult rodents. A variety of neuronal and gl ial markers as well. as three extracellular matrix (ECM) markers were examined with the hope of understanding factors that may affect the gr owth and migration of neurons from this region throughout development and in the adult. This study has characterized the subventricular zone of late embryonic, postnatal, and adult mice using several neuronal m arkers [TuJ1, nicotinamide adenine dinucleotide phosphate diaphorase ( NADPH-d), neuron-specific enolase (NSE)], glial markers [RC-2, vimenti n, glial fibrillary acidic protein (GFAP), galactocerebroside (Gal-C)] , ECM markers [tenascin-C (TN-C), chondroitin sulfate, a chondroitin s ulfate proteoglycan termed dermatan sulfate-dependent proteoglycan-1 ( DSD-1-PG)], stem-cell marker (nestin), and proliferation-specific mark er [bromodeoxyuridine (BrdU)]. TuJ1(+) and nestin(+) cells (neurons an d stem cells, respectively) persist in the region into adulthood, alth ough the numbers of these cells become more sparse as the animal devel ops, and they appear to be immature compared to the cells in surroundi ng forebrain structures (e.g., not expressing NSE and having few, if a ny, processes). Likewise, NADPH-d(+) cells are found in and around the SVZ during early postnatal development but become more sparse in the proliferative zone through maturity, and, by adulthood, only a few lab eled cells can be found at the border between the SVZ and surrounding forebrain structures (e.g., the striatum), and even smaller numbers of positive cells can be found within the adult SVZ proper. BrdU labelin g also seems to decrease significantly after the first postnatal week, but it still persists in the SVZ of adult animals. The disappearance of RC-2(+) (radial) glia during postnatal development and the persiste nce of glial-derived ECM molecules such as tenascin and chondroitin su lfate proteoglycans (as well as other ''boundary'' molecules) in the a dult SVZ may be associated with a persistence of immaturity, cell deat h, and a lack of cell emigration from the SVZ in the adult. (C) 1995 W iley-Liss, Inc.