The adult mammalian brain contains at least two populations of neural stem/precursor cells (NPCs) which are set a side during development for the function of repair and replacement throughout life (Lim & Alvarez-Bullya, 2016;Obernier & Alvarez-Bullya, 2019). One population is present in the ventricular-subventricular zone (SVZ) on the walls of the lateral ventricle. The neuroblasts generated by these NPCs migrate to the olfactory bulbs which are a considerable distance rostrally by chain migration along a course called the rostral migratory stream (RMS). There they become incorporated into the olfactory circuitry as functional interneurons contributing to fine odor discrimination. It is estimated that many thousands of new olfactory neurons are produced each day in the rodent brain.The second population of NSCs is present in the dentate gyrus of the hippocampus and pass through a series of developmental stages to become incorporated into the hippocampal circuitry as dentate granule neurons (Goncalves et al., 2016). Here they are involved in learning, memory and pattern separation.Both populations of NSCs have been investigated with the aim of improving the human condition. In the hippocampus, for example, methods to improve their rate of production, rate of differentiation or slowing their rate of loss during ageing are of considerable interest since if this were to translate to humans the implications for learning and memory in elderly populations or in neurological disease could be highly significant. In this regard, several growth factors and signaling molecules such as Wnt, Shh, BMP, and Notch play crucial roles in the promotion of NSC