Glia-like stem cells sustain physiologic neurogenesis in the adult mammalian carotid body.

Neurogenesis is known to occur in the specific niches of the adult mammalian brain, but whether germinal centers exist in the neural-crest-derived peripheral nervous system is unknown. We have discovered stem cells in the adult carotid body (CB), an oxygen-sensing organ of the sympathoadrenal lineage that grows in chronic hypoxemia. Production of new neuron-like CB glomus cells depends on a population of stem cells, which form multipotent and self-renewing colonies in vitro. Cell fate mapping experiments indicate that, unexpectedly, CB stem cells are the glia-like sustentacular cells and can be identified using glial markers. Remarkably, stem cell-derived glomus cells have the same complex chemosensory properties as mature in situ glomus cells. They are highly dopaminergic and produce glial cell line-derived neurotrophic factor. Thus, the mammalian CB is a neurogenic center with a recognizable physiological function in adult life. CB stem cells could be potentially useful for antiparkinsonian cell therapy.