Organoid timing gap challenges lab-grown minibrains as brain models

New research shows lab-grown brain organoids don’t mirror real brain development timing. In mouse-derived organoids, radial glial progenitors sometimes produce neurons too early, while later-stage progenitors overproduce, and about a third become fate-restricted to a single neuron type. The organoids also lack in vivo signals like blood vessels and extracellular cues that may synchronize development. This timing mismatch could limit organoids’ usefulness for modeling brain development and disease, prompting researchers to identify missing signals and test human-cell organoids to better mimic real brains.