title: A possible role for the immune system in adult neurogenesis: new insights from an invertebrate model.
abstract: Persistent neurogenesis in the adult brain of both vertebrates and invertebrates was previously considered to be driven by self-renewing neuronal stem cells of ectodermal origin. Recent findings in an invertebrate model challenge this view and instead provide evidence for a recruitment of neuronal precursors from a non-neuronal source. In the brain of adult crayfish, a neurogenic niche was identified that contributes progeny to the adult central olfactory pathway. The niche may function in attracting cells from the hemolymph and transforming them into cells with a neuronal fate. This finding implies that the first-generation neuronal precursors located in the crayfish neurogenic niche are not self-renewing. Evidence is summarized in support of a critical re-evaluation of long-term self-renewal of mammalian neuronal stem cells. Latest findings suggest that a tight link between the immune system and the system driving adult neurogenesis may not only exist in the crayfish but also in mammals.
authors.affiliation: Zoological Institute and Museum, Department of Cytology and Evolutionary Biology, Ernst-Moritz-Arndt University Greifswald, Soldmannstrasse 23, D-17489 Greifswald, Germany. Electronic address: steffen.harzsch@uni-greifswald.de.
authors.forename: Steffen
authors.initials: S
authors.lastname: Harzsch
authors.affiliation: Institut für Anatomie und Zellbiologie, Universitätsmedizin Greifswald, Friedrich-Loeffler-Str. 23c, D-17489 Greifswald, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: von Bohlen Und Halbach
mesh_terms: D000818:Animals; D003400:Astacoidea / Q000254:growth & development*; D001921:Brain / Q000166:cytology; D007107:Immune System / Q000502:physiology*; D007448:Invertebrates / Q000254:growth & development* / Q000276:immunology*; D008322:Mammals; D023421:Models, Animal; D055495:Neurogenesis / Q000276:immunology*; D009474:Neurons / Q000166:cytology
keywords: Immune system; Neurogenic niche; Neuronal stem cells; Persistent neurogenesis; Self renewal