Interaction between astrocytes and adult subventricular zone precursors stimulates neurogenesis.
Neurogenesis continues in the mammalian subventricular zone (SVZ) throughout life. However, the signaling and cell-cell interactions required for adult SVZ neurogenesis are not known. In vivo, migratory neuroblasts (type A cells) and putative precursors (type C cells) are in intimate contact with astrocytes (type B cells). Type B cells also contact each other. We reconstituted SVZ cell-cell interactions in a culture system free of serum or exogenous growth factors. Culturing dissociated postnatal or adult SVZ cells on astrocyte monolayers-but not other substrates-supported extensive neurogenesis similar to that observed in vivo. SVZ precursors proliferated rapidly on astrocytes to form colonies containing up to 100 type A neuroblasts. By fractionating the SVZ cell dissociates with differential adhesion to immobilized polylysine, we show that neuronal colony-forming precursors were concentrated in a fraction enriched for type B and C cells. Pure type A cells could migrate in chains but did not give rise to neuronal colonies. Because astrocyte-conditioned medium alone was not sufficient to support SVZ neurogenesis, direct cell-cell contact between astrocytes and SVZ neuronal precursors may be necessary for the production of type A cells.
Lim
D A
DA
The Rockefeller University, New York, NY 10021, USA. limd@rockvax.rockefeller.edu
Alvarez-Buylla
A
A
D000328:Adult; D001253:Astrocytes / Q000166:cytology* / Q000502:physiology; D002450:Cell Communication / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology; D002465:Cell Movement / Q000502:physiology; D002478:Cells, Cultured; D006801:Humans; D009474:Neurons / Q000166:cytology* / Q000502:physiology; D016548:Prosencephalon / Q000166:cytology* / Q000502:physiology