The search for neural progenitor cells: prospects for the therapy of neurodegenerative disease.

The etiology of many neurodegenerative diseases has been identified in recent years. Treatment of central nervous system (CNS) disease could focus on one or more steps that lead to cell loss. In the past decade, cell therapy and/or ex vivo gene therapy have emerged as possible strategies for the treatment of neurodegenerative diseases. The ability to grow CNS-derived neural progenitor cells using growth factors has been extremely useful to study diverse phenomena including lineage choice, commitment and differentiation. By virtue of their biological properties and their presence in the adult CNS, neural progenitors represent good candidates for multiple cell-based therapies for neural diseases. Further identification of the molecules that direct the differentiation of adult neural progenitors may allow their activation in vivo to induce self-repair. This review addresses the nature, distribution and regulation of neural stem cells and the potential for applying these cells to both structural CNS repair and gene therapy.