A team of European scientists has grown parts of a human brain in tissue culture from stem cells. Their work could help scientists understand the origins of schizophrenia or autism and lead to drugs to treat them, said Juergen Knoblich, deputy scientific director at the Institute of Molecular Biotechnology of the Austrian Academy of Science and one of the paper's co-authors.
The advance could also eliminate the need for conducting experiments on animals, whose brains are not a perfect model for humans.
To grow the brain structures, called organoids, the scientists used stem cells, which can develop into any other kind of cell in the body. They put the stem cells into a special solution designed to promote the growth of neural cells. Bits of gel interspersed throughout the solution gave the cells a three-dimensional structure to grown upon. In eight to ten days the stem cells turned into brain cells. After 20 days to a month, the cells matured into a size between three and four millimeters, representing specific brain regions, such as the cortex and the hindbrain.
Growing brain tissue this way marks a major advancement because the lab-grown brain cells self-organized, and took on growth patterns seen in a developing, fetal brain.
Currently, the organoids are limited to how big they can get because they do not have a circulatory system to move around nutrients.
Knoblich's team didn't stop of growing the brain organoids, though. They went a step further and used the developing tissue to study microcephaly, a condition in which the brain stops growing. Microcephalic patients are born with smaller brains, and impaired cognitive development. Studying microcephaly in mice doesn't help because human and mouse brains are too different.