Summary of the TTC-unstained lesion volumes in each group. Brain slices were stained with 2,3,5-triphenyltetrazolium chloride (TTC) to visualize the damaged lesions. A brain slice from the non-treated MCAO rats is shown for comparison (A). The TTC-stained brain slices from rats that were intravenously transplanted with 107 hTERT-MSCs 12 h after MCAO are shown in panel B. The sections were also counterstained with hematoxylin and eosin. Although the glial scar tissue and a large number of inflammatory cells were obvious in the lesion without cell transplantation (C), parenchymal brain tissue was greatly preserved in the treated group (D). Note that a small number of inflammatory cells were observed in the regions that may be heavily stressed by the ischemia. Panel E summarizes the TTC-unstained lesion volumes in each group. Scale bar = 3 mm (A, B), 20 μm (C, D).