Grow Your Own Brain




The earliest stages of brain development can now be modelled using three-dimensional tissues called “cerebral organoids”.

funzim brain

Stem cells have been blasting onto the scientific top news recently, and again they have shown here what their amazing potential is for future development. Recently, biomedical scientists have managed to transform human stem cells into tiny brains (approximately the size of a pea) that have a neural structure that is similar to the brain of a developing embryo. These stem cells are simply bathed in the correct mixture of nutrients and grown in a spinning chamber. Over a period of a few weeks, they will arrange themselves into a small spherical structure of white tissue which show complex features of a developing brain such as distinct layers and regions.

These structures are the best living models of human brains that have been created so far, and are referred to as “cerebral organoids”. It really is quite remarkable how these simple stem cell building blocks can organise themselves into something as complex as an embryonic brain just by simply providing the right lab conditions.

Brain

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This development has actually already been put to good use! The scientists at the Institute of Molecular Biotechnology of the Austrian Academy of Sciences in Vienna have already begun to use these tiny brains to investigate neuronal disorders. One in particular has been focused on, microcephaly, which the brain does not develop properly at the early stages. They now hope to continue and use this technique to study more complex conditions such as schizophrenia or autism. As of yet, there are no useful animal models that are available for studying these disorders.

This test confirmed what scientists already predicted about microcephaly – caused by several mutations in a gene called CDK5RAP2. They managed to do this by taking skin cells from a patient, reprogramming them into a “stem like” state, and then used them to grow these organoids, which actually turned out much smaller than usual. Through dissection of these organoids it was possible to discover the reason for their stunted growth.

It is unlikely that these methods can replace animal experiments entirely as it is not possible to duplicate the elegance with which it is possible to do genetics in animal models. However, is may be possible to reduce the number of experiments conducted on animals, in particular – ┬átoxicology or drug testing.

Looking to the future it may be possible to develop even larger organoids. At the moment, these structures cannot get any larger, this is because their interiors do not receive any oxygen or nutrients. The organoids require a blood supply, or the equivalent of one, if they ever intend to grow any larger. When this problem gets solved, it will be possible to capture events that occur later in the brain’s development, and this may lead to finding cures for disorders such as autism. There will of course be moral issues here, and it is possible that when this technology advances it focuses more using mouse cells instead of creating a human “brain in a dish”. Regardless, this is a gigantic leap forwards in science, so watch this space!