Breakthrough in Brain Research: Scientists Create a "Whole" Brain Organoid

Researchers at Johns Hopkins University have achieved a significant breakthrough by growing a lab-grown organoid that mimics an entire human brain. This "mini-brain," which includes various regions and even rudimentary blood vessels, opens a new era in studying complex neurological and psychiatric disorders such as autism, schizophrenia, and Alzheimer's disease.

What is a Brain Organoid and What Makes This New Achievement Unique?

Brain organoids are miniature, lab-grown structures derived from stem cells that mimic the development and organization of a real brain. Until now, most such models have reproduced only specific regions, such as the cortex or midbrain.

The team from Johns Hopkins University has, for the first time, been able to combine organoids from several key brain regions — the forebrain, midbrain, and hindbrain — into a single structure they call a "multiregion brain organoid" (MRBO).

The main innovation lies in the integration of the endothelial system into this structure — a complex of cells that form blood vessels. This not only allowed the connection of different brain regions but also created a semblance of the blood-brain barrier — a crucial element that protects the brain.

Why is This Important for Medicine?

• Comprehensive Study of Diseases:

  
  

  Disorders such as schizophrenia or autism affect not just one area but the entire brain. The new organoids allow observation of how a disease develops in real-time, affecting connections between different regions.

  
  

• Drug Testing:

  
  

  "Mini-brains" will become an ideal platform for testing new drugs. This can help screen out ineffective or unsafe medications before costly human clinical trials begin.

  
  

• Personalized Medicine:

  
  

  In the future, it may be possible to grow organoids from a specific patient's cells to tailor the most effective therapy for them.

The researchers note that the grown organoids resemble the brain of a 40-day-old human fetus in their development. They already demonstrate complex network activity between different regions.

This step forward in organoid engineering provides scientists with an unprecedented tool for unraveling the mysteries of the human brain and developing treatments for its most complex diseases.

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Source: The article "Multi-Region Brain Organoids Integrating Cerebral, Mid-Hindbrain, and Endothelial Systems" published in the journal Advanced Science. DOI: 10.1002/advs.202503768.