In vitro priming of SVZ-derived adult neural progenitor cells with lithium chloride enhances the formation of region-specific mature neurons 12 weeks after transplantation. (a through d) Representative confocal micrographs with orthogonal projections of BrdU-labeled lithium chloride-primed adult neural progenitor cells co-expressing DARPP-32, a marker of striatal medium-size spiny projection neurons retrogradely co-labeled with Fluorogold (FG) from the globus pallidus. Graphs comparing the proportion of transplanted BrdU-labeled cells co-expressing (e) DARPP-32, or (f) FG labeling 12 weeks after transplantation. Scale bar = 20 μm. *P < 0.05.