The adult mouse subependymal zone regenerates efficiently in the absence of tenascin-C.

The subependymal zone (SEZ) of the lateral ventricles of the adult mouse brain hosts neurogenesis from a neural stem cell population with the morphology of astrocytes (termed type-B cells). Tenascin-C is a large extracellular matrix glycoprotein present in the SEZ that has been shown to regulate the development of embryonic neural stem cells and the proliferation and migration of early postnatal neural precursors. Here we show that tenascin-C is produced by type-B cells and forms a layer between SEZ and the adjacent striatum. Tenascin-C deficiency resulted in minor structural differences in and around the SEZ. However, the numbers of neural stem cells and their progeny remained unaffected, as did their regeneration after depletion of mitotic cells using the antimitotic drug cytosine-beta-D-arabinofuranoside. Our results reveal a remarkable ability of the adult neural stem cell niche to retain proper function even after the removal of major extracellular matrix molecules.