In the talk today Freda will discuss the fact that one of the fundamental questions in human biology is how a pool of proliferating neural precursor cells (NPCs) in the embryo can ultimately generate the complex functional neural circuitry that comprises the adult mammalian brain. In that regard, this lecture will focus upon several aspects of that question, focusing upon the mammalian cerebral cortex and asking how NPCs are regulated both during normal development, and in genetic disorders that cause cognitive dysfunction. A second key question is whether the information that we derive from the study of developing NPCs can ultimately provide therapies for the injured or degenerating brain. An example of the potential success of such a strategy will also be discussed, focusing upon identification of pharmacological stem cell activators that can regulate signaling pathways in endogenous NPCs and in so doing, potentially enhance neural repair.