Human cortical organoids now fill most of a mouse cortex
A new mouse platform gives human cortical organoids enough space to model development, disease, and therapies with circuit- and behaviour-level readouts. Researchers removed glutamatergic neurons from the mouse neocortex and hippocampus, then filled the cavity with human stem-cell-derived tissue; the graft occupied most of the cortical volume and integrated with the mouse nervous system. The animals retained broad locomotion but showed selective changes in limb coordination and spontaneous behaviour, and the model produced behavioural readouts after injury to developing human cortical cells.