Researchers grow miniature "whole brains" to study diseases
Researchers at John Hopkins University want to use a new generation of complex minibrains to better understand neuropsychiatric disorders.
Annie Kathuria and her team examine a brain organoid under the microscope.
(Image: Will Kirk, Johns Hopkins University)
Scientists at Johns Hopkins University have grown a mini-brain in which tissue from several regions of the brain is connected and interacts with each other. They hope to usher in a new era of research into neuropsychiatric disorders. "Most brain organoids you see in scientific journals represent a single brain region, such as the cortex or the hindbrain or midbrain. We have grown a rudimentary whole-brain organoid", explains the lead author of the paper, Annie Kathuria.
Coherent construct
The so-called multi-region brain organoid developed by the research team is intended to replicate the development of the brain of a human fetus. According to the researchers, this is possible because it integrates organoids of the cerebrum, midbrain and hindbrain as well as blood vessel structures (endothelial organoids) into a coherent construct. This represents a new generation of brain organoids and a significant improvement in the modeling of brain development.
This is how the researchers proceeded: First, they grew nerve cells from individual brain regions and rudimentary blood vessels in separate laboratory dishes. The team then glued the individual parts together with proteins that enable the formation of connections between the tissues. As the tissues grew together, they began to generate electrical activity and react as a network. The team could also have observed the formation of an early blood-brain barrier. It serves as a barrier that protects the brain by controlling which molecules are allowed to enter the brain from the blood.
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Neuronal diversity
According to the researchers, the resulting brain organoid showed a wide variety of neuronal cell types with characteristics similar to those of a 40-day-old human fetus. They estimate the size of a brain from the laboratory at two to three millimeters. It contains six to seven million neurons, a fraction of the 86 billion neurons in an adult brain.
The whole-brain organoids should help to better understand neurological diseases. "Diseases such as schizophrenia, autism and Alzheimer's affect the whole brain, not just a part of it. If we understand what goes wrong in development at an early stage, we may be able to locate new targets for drug screening," says Kathuria. The researchers want to use the minibrains to observe emerging disorders in real time and check whether treatments are working.
The team has published its work open access in Advanced Science.
(dgi)
