Understanding Neurotoxicity: Building Human Mini-Brains From Patients' Stem Cells

Making your skin cells think – researchers create mini-brains from donated skin cells. It sounds like science fiction, but ten years ago Shinya Yamanaka’s lab in Kyoto, Japan, showed how to make stem cells from small skin donations. Now researchers at Johns Hopkins Bloomberg School of Medicine are making little brains from them. “We model the first two to three months of brain development”, says Thomas Hartung, directing Hopkins’ Center for Alternatives to Animal Testing. These cell balls are very versatile – you can study the effects of drugs or chemicals. This promises treatments for diseases like Parkinson’s, Alzheimer or Multiples Sclerosis. But also the disturbance of brain development, for example leading to autism, can be studied.

And they can do mini-brains probably from anybody. This opens up for personalized medicine. Cells from somebody with the genetic background contributing to any of these diseases can be invaluable to test the drugs of the future. Take autism – we know that neither genetics nor exposure to chemicals alone leads to the disease. Perhaps we can finally unravel this with mini-brains from the skin of autistic children? They bring the genetic background – the researchers bring the chemicals to test.

And these mini-brains are actually thinking. They fire electrical impulses and communicate via their normal networks, the axons and neurites. The size of a fly eye, they are just nicely visible. Most of the different brain cell types are present, not only various types of neurons.

“This is opening up for a more human-relevant research to study diseases and test substances”Hartung raves over these opportunities. They started to study viral infections, but stroke, trauma and brain cancer are on their list.

“In order to fully exploit this technology, we must make this easily available”, the Hopkins team believes. “This is in the best interest of patients and for saving animals.” It took them more than three years to make it running. Too long for a company interested in using it. Therefore, the team is currently creating a spin-off company, ORGANOME. They want to make available mini-brains by back-order and delivered within days by parcel service. “Nobody should have an excuse to still use the old animal models”,states Hartung firmly. How far are they? They believe they will have a product by fall. And the future? Customized brains for drug research – such as brains from Parkinson patients to test new Parkinson drugs. Effects of illicit drugs on the brain. Effects of flavors added to e-cigarettes? Screening to find chemical threat agents to develop countermeasures for terroristic attacks. Disease models for infections. The list is long. And the ultimate vision? A human-on-chip combining different mini-organs to study the interactions of the human body. Far away? Models with up to ten organs are actually already on the way.

For more information please contact the Hartung lab at the Bloomberg School of Public Health (CAAT@jhu.edu). Photo and video material is available upon request.