Adult neurogenesis is the process by which neural stem cells (NSCs) generate new neurons in the adult mammalian brain, which contributes to learning and memory and supports cognitive resilience during ageing. Deficits in adult neurogenesis have been associated with various neurodevelopmental and neuropsychiatric disorders, as well as neurodegenerative diseases.

In Drosophila melanogaster, early studies showed that this process relies on the reactivation and proliferation, in larval stages, of quiescent NSCs (also known as neuroblasts in D. melanogaster), which are generated during embryonic central nervous system development; moreover, it is dependent on nutrition — specifically, dietary amino acids. It was proposed that a mitogen derived from the fat body (the invertebrate functional analogue of mammalian liver and adipose tissue) promotes re-entry of NSCs into the cell cycle in the larval brain. However, the molecular mechanisms underlying this inter-organ communication and NSC reactivation remained elusive for nearly two more decades.