How does the brain build itself from a handful of precursor cells into billions of neurons organized in precise layers? Developmental neurobiologist Stephen Noctor explains the remarkable choreography of cell division, migration, and differentiation in the ventricular zone , where future neurons bounce up and down like yo-yos before embarking on journeys equivalent to climbing four Empire State Buildings. Subscribe for more from the Convergent Science Network podcast series. Stephen Noctor joins Paul Verschure and Tony Prescott at the BCBT summer school to describe his research on the precursor cells that generate the cerebral cortex. Using fluorescent labeling and time-lapse imaging in rat brain slices, Noctor has captured the movements of individual precursor cells as they undergo interkinetic nuclear migration , rapidly descending to the ventr ...