Five-year brain organoids mirror human development

In a significant advance for neuroscience, researchers have successfully maintained human brain organoids in a laboratory for more than five years, demonstrating that these miniature models of brain tissue can mimic key stages of human development and retain a cellular memory of their own growth. The study, published in the journal Nature, sets a new record for the longevity of such organoids and opens new avenues for studying brain development and disease.

The research team, led by scientists at Harvard University and the Broad Institute, grew the organoids from stem cells derived from human blood samples. These peppercorn-sized clumps of cells, each containing over a million cerebral cortex cells, were sustained in culture for over five years, more than three times longer than the previous record of 694 days set in 2021. The team analyzed 34 organoids at eight time points between six months and five years, monitoring their development with single-cell RNA sequencing.

The findings revealed that the organoids did not merely survive but continued to mature in a sequence that closely parallels normal human brain development. A key indicator was the pattern of DNA methylation, a...