Developmental control of neural cell number and type

Brain expansion is a defining feature of our biology, and how the brain develops shapes our experience as individuals. Our understanding of the ways in which neurodevelopmental variation determines how neural systems are constructed can be addressed in species that have simpler but analogous neural circuits, cell developmental pathways and patterns of genetic regulation. This project exploits the extreme levels of neurodiversity of Heliconiini butterflies to develop a unique model system of neurodevelopmental regulation. We previously identified major shifts in the cell population forming the mushroom bodies (insect learning and memory centres) in this tribe, with the number of intrinsic neural cells (Kenyon cells) varying 8-fold between closely related species. The expanded cell population is produced by a pool of derived intermediate progenitors and affects Kenyon cell sub-types differentially. This provides a novel insect system in which to explore the regulation of cell fate decisions analogous to those with critical importance for typical, and atypical, human brain development. We will use this system to understand the mechanisms governing expanded neural populations, altered production of cell types, their impacts on wider brain circuits, and their behavioural significance. This will advance our understanding of the fundamental principles and developmental pathways governing neurodevelopment.