The *in vitro* modeling of human brain connectomes is key to exploring the structure-function relationship of the central nervous system. This paper presents a novel microfluidic design that addresses the limitation of current *in vitro* brain models in recapitulating brain region heterogeneity. The device enables controlled and uniform deposition of cell populations in chambers of varying size and shape, tailoring neuron numbers from thousands to millions. By applying this design to neurofluidic devices, the authors offer new organ-on-a-chip platforms for neuroscience research, enhancing *in vitro* platforms for investigating human neurodegenerative diseases.

B. G. C. Maisonneuve, L. Libralesso, L. Miny, A. Batut, J. Rontard, M. Gleyzes, B. Boudra, J. Viera, D. Debis, F. Larramendy, V. Jost, T. Honegger