A scientific team in Ohio has managed to raise the most complete human brain yet, and plan to use it for testing drugs and trying to understand autism.
The brain is at the same stage of development as a five-week-old fetus and contains 99 per cent of the same cells that you'd find in an in-utero equivalent. It's about the size of a pencil eraser and took 15 weeks to grow from adult skin cells.
"It not only looks like the developing brain, its diverse cell types express nearly all genes like a brain," said Rene Anand, professor of biological chemistry and pharmacology at Ohio State University.
"We've struggled for a long time trying to solve complex brain disease problems that cause tremendous pain and suffering. The power of this brain model bodes very well for human health because it gives us better and more relevant options to test and develop therapeutics other than rodents."
The brain is remarkably complete and comes with a stunted spinal cord and all major regions of the standard human noggin. It includes multiple cell types and genes, signaling circuitry, and even a retina.
It was built by taking skin cells from an adult and converting them into induced pluripotent stem cells (iPSCs) that can be reprogrammed to form almost any type of tissue. It took 15 weeks to grow the brain and the team say they're going to carry on nurturing it until it gets to the equivalent of a 12-week-old human, and maybe longer.
"If we let it go to 16 or 20 weeks, that might complete it, filling in that 1 percent of missing genes. We don't know yet," Anand said.
The team wants to use the brain to study pain medications and to identify genetic issues that may cause autism, Alzheimer's, and Parkinson's disease. The US military's Defense Advanced Research Projects Agency (DARPA) is also interested in the research, Anand said, so that it could test for the effects of toxins and their antidotes.
Anand presented the details of his lab-grown brain at the 2015 Military Health System Research Symposium in Ft. Lauderdale, Florida, but hasn't filed a research paper for peer review because there is a patent pending on the technique for growing the brain.
If the technique can be mastered, it will open up an entirely new area of medical treatment, such as patients donating a few skin cells and having a replica brain built for testing the effects of medicines without risking negative effects themselves. ®