Organogenesis, the development of organs, is a hot topic in biology nowadays. With the current technology researchers are now able to grow organs, and thus mimic organogenesis. To create artificial brains is, off course, a hot topic within the hot topic. Though, so far, no method has ever grown a succesfull forebrain which represents an actual developing forebrain in an embryo. Intrinsic methods had a few problems with them.
First of all, the machines where the organoids were being grown in were way to big and expensive to be very applicable. Second, previous methods had a very low reproducibility. Every organoid grown, was completely different from another. This also decreases the applicability. And third, the biggest problem, the organoids didn't have a specific layer, the Outer Subventricular Zone (oSVZ). Without this layer, the forebrain organoid is nowhere near representable.
However, researchers now have achieved something very special in this field. They have created the so called SpinΩ. This is a bioreactor in which specific parts of the brain can be grown. SpinΩ solves the first problem, because it is a machine simply made out of plastic printed by a 3D-printer. It is a much cheaper method, and isn't bigger than a shoebox.
On top of that, all the organoids showed a similar structure and development, thus the reproducibility increased significantly. Figure 1 shows the development of the forebrain which has been grown with SpinΩ.
Figure 1. Developing forebrain organoid grown with SpinΩ.
And most amazingly, the organoids grown with SpinΩ actually showed a perfect development of the oSVZ. This layer consists of glia cells, a specialised type of neuron cells. Shown in figure 2 is an immunostaining of a forebrain organoid. The oSVZ is indicated by the yellow dots. These dots are the bounderies of the layer, consisting of glia cells.
Figure 2. The yellow dots resemble the bounderies of the oSVZ.
With this new method, almost a completely new field of research has opened up. The researchers already put this in practice. They exposed their grown organoids to the ZIKA-virus. The organoids showed astonishing resemblance with a forebrain of an embryo infected by the virus. This encourages new research in all sorts of brain diseases. As of today, no medicin has been found for the ZIKA-virus but with this method, maybe this will change.
One small thing I was personally wondering is, if these organoids keep getting better and better, will they eventually be able to think? Think about that for a second...