Human neural stem cells improve cognitive function of aged brain

The capability for in vitro expansion of human neural stem cells (HNSCs) pr ovides a well characterized and unlimited source alternative to using prima ry fetal tissue for neuronal replacement therapies. The HNSCs, injected int o the lateral ventricle of 24-month-old rats after in vitro expansion, disp layed extensive and positional incorporation into the aged host brain with improvement of cognitive score assessed by the Morris water maze after 4 we eks of the transplantation. Our results demonstrate that the aged brain is capable of providing the necessary environment for HNSCs to retain their pl uripotent status and suggest the potential for neuroreplacement therapies i n age-associated neurodegenerative disease. NeuroReport 12:1127-1132 (C) 20 01 Lippincott Williams & Wilkins.