Scientists have made an exciting breakthrough in the quest to better understand diseases like dementia, autism, and schizophrenia. For the first time, they’ve created lab-grown mini brains with a functional output, even showing that the little blobs of tissue can control muscle contractions.
Mini brains, technically called cerebral organoids, are 3D tissues derived from human stem cells that organize themselves in such a way that they mimic a fetal brain. Studying these tiny structures can help scientists learn more about how our own brains work.
The new research, published in Nature Neuroscience, was conducted by researchers at the MRC Laboratory of Molecular Biology in Cambridge, UK. The team took back muscle and a 1-millimeter piece of spinal cord from a mouse and placed it near a mini brain to see what would happen. Amazingly, neurons from the little brain extended out and attached themselves to the spinal cord. This connection then allowed the organoid to control the muscle via electrical impulses, causing it to contract.
“This is the first demonstration of a functional output from cerebral organoid tissues in a dish,” the MRC Laboratory noted in a statement.
While the miniature brains can control muscle, they are still incredibly tiny and uncomplicated compared to our brains, and cannot think or feel emotions.
“It’s still a good idea to have that discussion every time we take it a step further,” research leader Madeline Lancaster told The Guardian. “But we agree generally that we’re still very far away from that.”
In addition to showing that organoids can control muscle, the team also found a clever way to increase their lifespan. Normally, lab-grown mini brains are kept submerged in a nutrient-rich liquid, but this means they can’t absorb much oxygen, limiting their growth. However, team member Stefano Giandomenico came up with a solution to this problem. He placed slices of mini brain on a porous membrane so that it was partially exposed to a nutrient-rich liquid beneath it and partially exposed to the air above. This meant the brain tissue could survive for longer and develop more, allowing the researchers to see connections form between brain regions under the microscope.
The researchers note that studying these mini brains could help us better understand how the central nervous system develops and give us new insights into certain diseases. In particular, the brain models could help scientists study psychiatric conditions that involve problems with neuronal connectivity, such as autism, depression, and schizophrenia. Meanwhile, the little brains could tell us more about conditions linked to disrupted brain connectivity, like dementia and strokes.
“Obviously we’re not just trying to create something for the fun of it,” Lancaster told The Guardian. “We want to use this to model diseases and to understand how these networks are set up in the first place.”