NES and Stroke: The results in this present study showed that Sox2+, DCX+, and BrdU+ cell numbers in SGZ were much higher in As IV group compared with control group in vivo (Figures 2A–D) and more Nestin+ and Sox2+ cells in the neurospheres of NSCs and enlarged diameters in both 10 nM and 100 nM As IV groups (Figures 2E), which indicated that As IV could significantly activate the stemness of NPCs and promote neurogenesis in the ipsilateral hippocampus after stroke.