Accumulating evidence indicates that neural stem cells (NSCs) are not restricted in certain regions of the brain but point towards multiple NSC niches. However, the mechanism by which these structures communicate long distance remains unclear. Recently, a new player in the neurovascular unit has been described, the perivascular meningeal stem cells. The scope of the EU-funded MENINGES-NET (Meninges: a new perivascular stem cells niche for widespread neurogenesis) project was to demonstrate that these cells contribute to postnatal brain neurogenesis by migrating to the brain parenchyma along vessels. To observe the migration of perivascular cells, researchers labelled meningeal cells of new-born mice with a red dye. They observed a rapid and progressive spreading of labelled cells from the meninges initially onto the surface of the brain and then to the lateral ventricles. Thirty days later, these cells were located in the cerebral cortical layers and exhibited primarily a neuronal morphology. None of these cells had differentiated into oligodendrocyte precursors or microglia. To conclusively demonstrate that only perivascular cells led to cortical neuron formation, researchers employed a gene fate mapping approach and specifically tracked down this cell population. Collectively, their data demonstrated the capacity of quiescent embryonically-derived meningeal cells to migrate into the brain parenchyma and give rise to functional cortical neurons. The findings of the study provide fundamental insight into brain neuronal biology and highlight the importance of perivascular tissue as a reservoir of neurogenic cells. This broadens the concept of brain plasticity and suggests that these cells could be exploited therapeutically.
Brain, neurogenesis, neural stem cells, perivascular meningeal stem cells, parenchyma