Scientists Cultivate New 'Whole-Brain' Organoid
Beijing, July 29 (Science and Technology Daily) — Researchers at Johns Hopkins University have developed a new type of "whole-brain" organoid that not only contains neural tissues from multiple brain regions but also has preliminary vascular structures. Published in the journal Advanced Science, this achievement demonstrates the first successful integration of various brain region tissues into a unified, functional organoid. The breakthrough is expected to open new avenues for studying complex neuropsychiatric disorders such as autism and schizophrenia.
Most brain organoids mentioned in current research represent only a single brain region, such as the cerebral cortex, hindbrain, or midbrain. In contrast, the newly developed structure is a preliminary "whole-brain" organoid, referred to by researchers as a "multi-region brain organoid" (MRBO).
To construct the whole-brain organoid, researchers first generated neural cells from different brain regions and preliminary vascular structures in separate culture dishes. They then assembled these components using an adhesive "bio-glue" protein, enabling them to establish connections during development. As the tissues fused, the organoid not only generated electrical activity but also developed the ability to respond as an integrated neural network.
In terms of cellular diversity, MRBO closely resembles the early developmental stage of the human embryonic brain. It contains approximately 80% of common neural cell types, with an overall structure comparable to that of a human fetal brain at around 40 days of development.
Although its volume is much smaller than that of a real human brain — containing only about 6 to 7 million neurons, compared to the hundreds of billions in an adult brain — the organoid provides an unprecedented human brain cell model for studying whole-brain diseases.
Furthermore, researchers observed early signs of blood-brain barrier formation, a structure of great significance in drug screening and neurological disease research.
In the future, using whole-brain organoids to test new drugs is expected to improve the success rate of neuropsychiatric drug development. Currently, the failure rate of such drugs in the first phase of clinical trials is as high as 96%, largely because preclinical research still relies heavily on animal models. Human brain organoids, which more closely mimic real developmental processes, are poised to significantly enhance drug screening efficiency.
Researchers note that diseases such as schizophrenia, autism, and Alzheimer's affect the entire brain rather than a single region. Gaining earlier insights into the origins of these diseases could lead to the discovery of entirely new therapeutic targets.