Stem Cell Biology in the Central Nervous System

In a series of papers published in the 1960s, Joseph Altman and colleagues reported that certain regions of the rat brain contained dividing cells capable of generating progeny with a neuronal morphology. Evidence for cell proliferation in the rat and mouse already existed, but conventional wisdom at the time was that the adult mammalian brain was completely incapable of regeneration, and that neurons were formed only during development. Because technical limitations made verifying the neuronal nature of cells difficult, Altman’s discoveries were met with great skepticism. Decades later, continued research and technical progress have led to unambiguous demonstration of adult neurogenesis. This chapter considers the nature of the neural stem cells responsible for generation of new neurons and glia in the adult CNS, their role in certain tumors, and the potential cell-based therapies they represent.