In our brains, neurons form intricate networks that allow electrical signals to flow in an efficient and directional manner between brain regions, ensuring that information ends up in the right destination. Neuroscientists have struggled to reproduce these intricate, one-way patterns of electrical exchange in traditional cell cultures. Ioanna Sandvig, Axel Sandvig, Nicolai Winter-Hjelm and Katrine Hanssen show how the directional flow of information can be successfully mimicked using ‘microfluidic platforms’ developed at NTNU NanoLab, which feature microscopic networks of channels and chambers.