Neural stem cells and their role in recovery processes in the nervous system.

Published data and our own results on the identification, cultivation, and potential therapeutic utilization of regional stem cells from humans and animals are reviewed. Pluripotent stem cells have been shown to proliferate in the subventricular zone of the lateral ventricles and the subgranular zone of the dentate gyrus of the hippocampal formation in adult human and animal brains. Data on the hierarchical organization of genetic networks in controlling individual development suggest a possible functional role for repeat mini-and microsatellite DNA sequences in stem cell differentiation. Methods of using human bone marrow as a source of stem cells for restoring damaged tissue in the brain are discussed. Heat-shock proteins have been found to block the formation of glial scars after neural transplantation. The viability of stem cells after transplantation can be increased by transfer of genes for neurotrophic growth factors into the genomes of the neurons undergoing transplantation.