If you keep even a casual eye on the world of medical research, then you'll known that animal testing is a ubiquitous part of the process. New drugs are routinely tried out on laboratory animals, usually rodents, before clinical trials are considered. Now, researchers at Johns Hopkins Bloomberg School of Public Health have developed a possible alternative, creating "mini-brains" made up of a similar mix of cells and neurons found in the human brain.

The use of laboratory animals is extremely widespread, but an astounding 95 percent of medicines that appear promising in rodent testing are found to be ineffective once human trials are conducted. Developing an effective alternative to the practice would represent a huge step forward in the drug development process, not to mention the ethical leap it would represent.

The most important fact to consider when looking at the Johns Hopkins team's possible alternative is that the mini-brains are derived from human cells, making it much more likely that the observed results will more closely resemble what could be expected in full human trials.

From a physical point of view, the new approach couldn't be much more different. Rather than using living creatures of a different species, the researchers turned to tiny bundles of cells just 350 micrometers in diameter. Just visible to the human eye, hundreds to thousands of identical mini-brains can be produced in a single batch, and as many as 100 of them can reside and grow within a single petri dish.

The tiny, brain-like bundles of cells are made up of adult skin cells that have been genetically reprogrammed to an embryonic stem cell-like state, and then engineered to grow into brain cells. After two months of cultivation, the mini-brains developed four types of neurons and two types of support cells (oligodendrocytes and astrocytes).

Study lead Thomas Hartung is in the process of building a company called Organome to produce the mini-brains on a larger scale. He hopes that production will begin later this year, and that as many institutions as possible get on board to test out the new method. In the long run, it could be the start of a big change in the drug development world.

"While rodent models have been useful, we are not 150-pound rats," said study lead Thomas Hartung. "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."

Source: Johns Hopkins