Vascular niche for adult hippocampal neurogenesis

TLDR

Adult hippocampal neurogenesis occurs in the subgranule zone, a proliferative niche whose S‑phase cell phenotypes and interactions with neighboring cells, including mesenchyme‑derived and circulating factors, remain poorly understood. We found that dividing cells cluster around blood vessels, with roughly 37 % expressing endothelial markers, and that most newborn endothelial cells are transient, indicating that adult neurogenesis occurs within an angiogenic niche. © 2000 Wiley‑Liss, Inc.; Neurol.

Abstract

The thin lamina between the hippocampal hilus and granule cell layer, or subgranule zone (SGZ), is an area of active proliferation within the adult hippocampus known to generate new neurons throughout adult life. Although the neuronal fate of many dividing cells is well documented, little information is available about the phenotypes of cells in S-phase or how the dividing cells might interact with neighboring cells in the process of neurogenesis. Here, we make the unexpected observation that dividing cells are found in dense clusters associated with the vasculature and roughly 37% of all dividing cells are immunoreactive for endothelial markers. Most of the newborn endothelial cells disappear over several weeks, suggesting that neurogenesis is intimately associated with a process of active vascular recruitment and subsequent remodeling. The present data provide the first evidence that adult neurogenesis occurs within an angiogenic niche. This environment may provide a novel interface where mesenchyme-derived cells and circulating factors influence plasticity in the adult central nervous system. J. Comp. Neurol. 425:479–494, 2000. © 2000 Wiley-Liss, Inc.