Scientists may have found a way to study rare, debilitating brain diseases: by producing “cerebral organioids,” miniature, three-dimensional human brain-like structures.
Sergiu Pasca and his colleagues from the Stanford University School of Medicine produced mini-brains in a dish that suffer from Timothy syndrome. The largest mini-brains are only 4 millimeters across—roughly the size of a sea slug or jellyfish brain—but they give insight into how the different regions in the brains fuse during gestation.
Timothy syndrome is a rare disorder characterized by malformations, neurological defects, heart arrhythmias, autism spectrum disorders, and a whole slate of devastating disorders. Oftentimes, it ends in early childhood death. Studying it has been incredibly difficult.
Three patients who suffered from Timothy syndrome, severe epilepsy, and autism donated cells from their brains. These were then returned to an embryo-like stem cell state with the use of now-standard techniques. After given proper nutrients, the stem cells grew into brain cells and eventually into two little balls known as cortical spheroids. One mimicked a deep region of the brain and another the cortex.
After the two sphoriods were fused together, the scientists observed the neurons’ behavior for days. In a healthy brain, the neurons from the deep region migrate to neurons in the cortex to form circuitry that helps with things like language, judgment, planning, and thought. Yet the lab-produced neurons were jumpier and more migratory than normal neurons.
A similar study at Harvard University developed organioids for at least nine months, a new record. The researchers found a diverse group of neurons not seen in previous mini-brains, a level that more closely mimicked real brains.
These studies are part of the exploding field of cerebral organioids, a discipline that has sparked some controversy. Since their creation in 2013, they have been at the center of an ethical debate that includes questions of whether these cells can suffer, feel pain, or be conscious.
Still, scientists are excited about the new opportunities that can come from studying these lab-grown brains. Here’s Sharon Begley reporting for STAT:
“This shows that the approach has much greater potential than we ever imagined,” said Juergen Knoblich, of the Institute of Molecular Biotechnology in Austria, a pioneer in creating cerebral organoids who was not involved in either study. “They’ve shown that if you keep [the mini-brain] growing for a long enough time, it will generate the whole repertoire of cells we see in the human brain.”
Scientists hope these brains-in-a-dish will mimic neurological diseases like schizophrenia, autism, and Alzheimer’s to reveal what goes wrong and what, if anything, can they do to treat them.
