الگوی توزیع و فراوانی سلولهای بنیادی و پیش ساز عصبی در طول محور بطنی مغز موش بالغ

Title

Mapping the frequency and distribution of neural stem and progenitor cells throughout the ventricular neuraxis of the adult mouse brain

English Abstract

Introduction: It is now clear that adult mammalian brain contains a population of neural precursor cells (neural stem and progenitor cells). Given the paucity of information regarding the distribution of neural precursor cells in the adult mammalian brain we employed three distinct assays, the neurosphere assay (NSA), neural colony forming cell assay (N-CFCA) and label retaining cell (LRC) approach, to compile a detailed atlas of the frequency and distribution of these cells along the adult mouse brain ventricular neuraxis. We also sought to determine whether these three methodologies have the ability to detect similar populations of NSCs. Materials and Methods: Brains were harvested and serially Vibratome and Cryo sectioned (400 and 14 μm/section respectively) starting at the level of the olfactory bulb. The periventricular region (PVR) was then microdissected from each section and transferred to neurosphere and N-CFCA culture conditions. The absolute number of neurospheres, Colonies and LRCs in each region were counted and plotted according to their rostral-caudal distribution. Results: The NSA, N-CFCA, and LRC approach each detected precursor cells throughout the ventricular neuraxis, totaling 3730±276, 4275±124, and 5292±102 respectively. However, the number of precursors detected in individual 400μm sections varied from a minimum of 8 to a maximum of 891 depending upon the rostral-caudal coordinate assayed. More importantly, by employing the N-CFCA to enumerate NSC-derived colonies we now report that rather than occurring throughout the rostral-caudal neuraxis, NSCs are absent from four distinct regions. Conclusion: In addition to mapping the frequency and distribution of neural precursor cells along the brain ventricular neuraxis, our results suggest that while each methodology detects equivalent numbers of neural precursor cells, both the NSA and LRC approach overestimates the number of endogenous NSCs. These results highlight the need for caution when employing these methodologies to detect NSCs in vitro and in vivo.

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