Human Brain Organoids Mature for 5 Years, Retaining a Cellular Memory of Time
Updated
Updated · Nature.com · Aug 19
Human Brain Organoids Mature for 5 Years, Retaining a Cellular Memory of Time
3 articles · Updated · Nature.com · Aug 19
Summary
Researchers kept human cortical organoids alive for more than 5 years and found their gene-expression and DNA-methylation changes tracked time in culture, with epigenetic age correlating closely with chronological age.
Across 110 organoids and 424,720 cells, the models shifted from fetal-like states toward late prenatal and postnatal signatures, showing that long-term organoids can mirror slow human brain maturation rather than only early development.
An activity-permissive medium improved survival and maturity of excitatory neurons, boosting synaptic density by 1 year and preserving robust network bursts in all 9 of 9 organoids at 1 year, versus none in 8 of 8 standard-culture organoids.
In mixed-age chimeric organoids, progenitors from 9- to 12-month-old organoids rapidly generated later neuronal fates and skipped earlier ones, indicating the cells retain a memory of time already spent developing.
The findings position long-lived organoids as a model for otherwise inaccessible postnatal human brain development and for studying disorders tied to maturation and aging.