Primary Neuronal Precursors in Adult Crayfish Brain: Replenishment from a Non-neuronal Source

作者：Jeanne L. Benton, Yi Zhang, Colleen Kirkhart, D. C. Sandeman, Barbara S. Beltz · 发表于：BMC Neuroscience · 年份：2011 · DOI：10.1186/1471-2202-12-53 · 被引用次数：37 · 研究领域：Neurogenesis and neuroplasticity mechanisms、Neurobiology and Insect Physiology Research、Developmental Biology and Gene Regulation

BACKGROUND: Adult neurogenesis, the production and integration of new neurons into circuits in the brains of adult animals, is a common feature of a variety of organisms, ranging from insects and crustaceans to birds and mammals. In the mammalian brain the 1st-generation neuronal precursors, the astrocytic stem cells, reside in neurogenic niches and are reported to undergo self-renewing divisions, thereby providing a source of new neurons throughout an animal's life. In contrast, our work shows that the 1st-generation neuronal precursors in the crayfish (Procambarus clarkii) brain, which also have glial properties and lie in a neurogenic niche resembling that of vertebrates, undergo geometrically symmetrical divisions and both daughters appear to migrate away from the niche. However, in spite of this continuous efflux of cells, the number of neuronal precursors in the crayfish niche continues to expand as the animals grow and age. Based on these observations we have hypothesized that (1) the neuronal stem cells in the crayfish brain are not self-renewing, and (2) a source external to the neurogenic niche must provide cells that replenish the stem cell pool. RESULTS: In the present study, we tested the first hypothesis using sequential double nucleoside labeling to track the fate of 1st- and 2nd-generation neuronal precursors, as well as testing the size of the labeled stem cell pool following increasing incubation times in 5-bromo-2'-deoxyuridine (BrdU). Our results indicate ...