During pregnancy, the human brain starts to develop at around 3/4 weeks of gestation. This is the beginning of a long process to maturity that is not complete for 20 years.
Formation of the most complex structure in the known universe is an event which will normally only occur inside the womb. However, scientists have now managed to produce the first “mini-brains” in the laboratory.
In an article published online by Nature yesterday, scientists at the Institute of Molecular Biotechnology in Vienna reported that they have grown cerebral organoids – or “mini-brains” – of specialised brain cells. To do this the team began with a type of cell called a pluripotent stem cell. This is a cell which has the potential to become almost any other cell in the body. In addition to this, they also used induced pluripotent stem cells (iPS cells) – cells that have been reprogrammed so that they behave like pluripotent cells.
Using specific growth factors and conditions, the stem cells were coaxed into becoming neuroectoderm tissue. This is the name given to cells in the embryo that later become the nervous system. The neuroectoderm tissue was added to a gel scaffold, which allowed more complex structures to grow. To enhance nutrient absorption, the tissue was spun in a spinning bioreactor,
In just 20-30 days defined brain regions had formed. After 2 months, the cerebral organiods reach their maximum size (~4 mm in diameter, roughly half the size of a tic-tac ). In the article, it states that the tissues “could survive indefinitely (currently up to 10 months) when maintained in a spinning bioreactor”
This research is likely to have a big impact on our understanding of how the brain develops. Not only could it help to unravel one of the greatest mystery’s plaguing mankind, but it also has the potential lead to brand new insights into mental disorders such as schizophrenia and autism.
Though nowhere near as complicated as an actual human brain, these “mini-brains” mean that we are one step closer to solving the riddle of what really goes on inside our heads.
If you would like to find out more about the mini-brains, you can read the nature article here.