Researchers at the Johns Hopkins Bloomberg School of Public Health say they have developed tiny “mini-brains” made up of many of the neurons and cells of the human brain – and even some of its functionality – and which can be replicated on a large scale.
The researchers say that the creation of these “mini-brains,” which will be discussed at the American Association for the Advancement of Science conference in Washington, DC on February 12 at a press briefing and in a session on February 13, could dramatically change how new drugs are tested for effectiveness and safety, taking the place of the hundreds of thousands of animals used for neurological scientific research in the United States. Performing research using these three-dimensional “mini-brains” – balls of brain cells that grow and form brain-like structures on their own over the course of eight weeks – should be superior to studying mice and rats because they are derived from human cells instead of rodents, they say.
“Ninety-five percent of drugs that look promising when tested in animal models fail once they are tested in humans at great expense of time and money,” says study leader Dr. Thomas Hartung, the Doerenkamp-Zbinden Professor and chair for evidence-based toxicology at the Bloomberg School. “While rodent models have been useful, we are not 150-pound rats. And even though we are not balls of cells either, you can often get much better information from these balls of cells than from rodents.
“We believe that the future of brain research will include less reliance on animals, more reliance on human, cell-based models.”
Dr. Hartung and his colleagues created the brains using what are known as induced pluripotent stem cells (iPSCs). These are adult cells that have been genetically reprogrammed to an embryonic stem cell-like state and then are stimulated to grow into brain cells. Cells from the skin of several healthy adults were used to create the mini-brains, but Hartung says that cells from people with certain genetic traits or certain diseases can be used to create brains to study various types of pharmaceuticals. He says the brains can be used to study Alzheimer’s disease, Parkinson’s disease, multiple sclerosis and even autism. Projects to study viral infections, trauma and stroke have been started.