Immunohistochemistry staining for human mesenchymal stem cells in whole brain sections of mice. Whole brain sections of each mice (4 μm) were proceeded immunohistochemistry staining of β2 microglobulin for hMSCs. Photographs were taken from the view of 100, 200 or 400-folds microscopy and the scale bar was 100 μm. (A-C) In IV-hMSC-Tg group, hMSCs were located over the cerebellar white matter (A), molecular layer, and the lumens of blood vessels in white matter (B). Large clusters of grafted hMSCs were detected within cerebral cortex as arrows (C). (D-G) In IC-hMSC-Tg group, positive brown signals were not detected over cerebellar white matter, molecular layer, or the Purkinje cell layer (D), but limited to a few lumen of blood vessels (E) and a few scattered cells in cerebral cortex (F). Positive signals of hMSCs were detected over the injection site beneath the dorsal surface of medulla (G), which was adjacent to the cerebellum. (H, I) No signals were detected in the cerebellar sections of Control-Wt (H) and Control-Tg mice (I).