Longitudinal tracking of hemocyte populations in vivo indicates lineage relationships and supports neural progenitor identity in adult neurogenesis.

Adult neurogenesis, which takes place in both vertebrate and invertebrate species, is the process by which new neurons are born and integrated into existing functional neural circuits, long after embryonic development. Most studies in mammals suggest that self-renewing stem cells are the source of the new neurons, although the extent of self-renewal is a matter of debate. In contrast, research in the crayfish Procambarus clarkii has demonstrated that the neural progenitors producing adult-born neurons are capable of both self-renewing and consuming (non-self-renewing) divisions.

Adult neurogenesis in crayfish: Identity and regulation of neural progenitors produced by the immune system.

Adult-born neurons are incorporated into brain circuits in the crayfish , as in many vertebrate and invertebrate species. Adult neurogenesis depends on several conserved features, including the presence of neurogenic niches housing progenitor cells and the expansion, migration, and differentiation of their daughters, the neural precursor cells. However, in contrast to mammalian species, the progenitors initiating the neurogenic lineage in do not undergo long-term self-renewal.