0000000000765531
AUTHOR
Bettina Seri
Astrocytes give rise to new neurons in the adult mammalian hippocampus
Neurogenesis in the dentate gyrus of the hippocampus persists throughout life in many vertebrates, including humans. The progenitors of these new neurons reside in the subgranular layer (SGL) of the dentate gyrus. Although stem cells that can self-renew and generate new neurons and glia have been cultured from the adult mammalian hippocampus, the in vivo primary precursors for the formation of new neurons have not been identified. Here we show that SGL cells, which express glial fibrillary acidic protein and have the characteristics of astrocytes, divide and generate new neurons under normal conditions or after the chemical removal of actively dividing cells. We also describe a population o…
Cell types, lineage, and architecture of the germinal zone in the adult dentate gyrus
New neurons continue to be born in the subgranular zone (SGZ) of the dentate gyrus in the hippocampus of adult mammals, including humans. Previous work has shown that astrocytes function as the progenitors of these new neurons through immature intermediate D cells. In the first part of the present study, we determined the structure of each of these progenitors and how they are organized in three dimensions. Serial-section reconstructions of the SGZ, using confocal and electron microscopy demonstrate that SGZ astrocytes form baskets that hold clusters of D cells, largely insulating them from the hilus. Two types of glial fibrillary acidic protein-expressing astrocytes (radial and horizontal)…