A morphology independent approach for identifying dividing adult neural stem cells in the mouse hippocampus

Background: Type 1 adult hippocampal neural stem cells (AH-NSCs) continue to generate neurons throughout life, albeit at a very low rate. The relative quiescence of this population of cells has led to many studies investigating factors that may increase their division. Current methods of identifying dividing AH-NSCs in vivo require the identification and tracing of radial processes back to nuclei within the subgranular zone. However, caveats to this approach include the time-intensive nature of identifying AH-NSCs with such a process, as well as the fact that this approach ignores the relatively more active population of horizontally oriented AH-NSCs that also reside in the subgranular zone. Results: Here we describe, and then verify using Hes5::GFP mice, that labeling for the cell cycle marker Ki67 and selection against the intermediate progenitor cell marker TBR2 (Ki67(+ve); TBR2(-ve) nuclei) is sufficient to identify dividing horizontally and radially oriented AH-NSCs in the adult mouse hippocampus. Conclusions: These findings provide a simple and accurate way to quantify dividing AH-NSCs in vivo using a morphology-independent approach that will facilitate studies into neurogenesis within the hippocampal stem cell niche of the adult brain. Developmental Dynamics 247:194-200, 2018. (c) 2017 Wiley Periodicals, Inc.