This lecture covers the reprogramming of induced pluripotent stem cells, neural stem cells during brain development, neural tube formation, regional differences in neural stem cells, and the similarities between adult and embryonic neural stem cells. It also discusses the existence of adult neural stem cells, evidence of cell division in the adult mammalian brain, and seasonal changes in brain volume in songbirds. The lecture explores tools to study adult neurogenesis, genetic lineage tracing, and the complex process of adult neurogenesis, including stem cell maintenance, differentiation, neuronal integration, and functional significance.