Now out on bioRxiv: https://doi.org/10.1101/2024.01.12.575349, using chicken embryos as a model system, we investigated how the embryonic brain expands and departs in morphology from the spinal cord early in development. The neural tube is the embryonic precursor of the central nervous system and has a positive fluid pressure within its lumen (Desmond et al. 2005). By perturbing lumen pressure early in development, we found that it drives thinning of the hindbrain dorsal tissue and brain expansion, whilst the spinal cord resists the pressure and holds its shape. We investigated the mechanical properties of the hindbrain and spinal cord using ferrofluid …