Johns Hopkins University researchers have created the world’s first whole-brain organoid that integrates tissues from all major brain regions, complete with rudimentary blood vessels and neural activity that mimics a 40-day-old human fetal brain. Published in Advanced Science, the breakthrough could transform how scientists study neuropsychiatric disorders and test new treatments.

The multi-region brain organoid (MRBO) represents a major advance over existing brain organoids, which typically replicate only single brain regions like the cortex or midbrain. “We’ve made the next generation of brain organoids,” said lead researcher Annie Kathuria, an assistant professor in Johns Hopkins’ Department of Biomedical Engineering. “Most brain organoids that you see in papers are one brain region, like the cortex or the hindbrain or midbrain. We’ve grown a rudimentary whole-brain organoid.”