Our research has recently focused on the therapeutic potential of human NSCs（hNSCs). Whentransplanted in the form of neuro-spheroids into the LV of 24-month-old memoryimpaired rats，thesehNSCs displayed extensive migration and incorporation into the aged host brain. Examination ofthese brains by immunohistochemistry revealed that tra-nsplanted hNSCs differentiated into neuronsand astrocytes in the regions of the bil-ateral cingular and parietal cortexes and hippocampus（Figs.2-3). These rats showeda significant improvement of cognitive score as assessed by the Morriswater maze 4 weeks after the transplantation。