Cerebral Organoids

Cerebral Organoids

  • Abdullah Iqbal

While we were watching television or pondering what to ask for a Christmas gift, a major breakthrough was reported in November 2018.

In a ground-breaking development from the University of California, cerebral organoids or ‘mini brains’ were grown in a laboratory and, astoundingly, have produced brain waves which are similar to that of a premature baby. They are truly deserving of the name ‘mini brains’ for these organoids are only 4mm across.

Alysson Muotri and his team of neuroscientists used stem cells to grow the mini brains: these cells are truly fascinating because of their ability to turn into almost all other cell types, with the careful addition of a few special ingredients known as transcription factors.

Such a discovery may sound like the stuff of science fiction – but it’s not completely like in the fairy-tales. It took 10 long months for the mini brains to mature enough produce these signals. In the costly world of neuroscience research, that’s a long time. So, was this discovery worth the wait? Muotri’s team and neurodevelopmental scientists across the world certainly think so. This advancement could help scientists understand early brain development, which has been near impossible due to the difficulty in getting foetal samples or examining foetuses in utero.

By replicating the early brain, scientists will be able to compare the differences in development, structure and function of the normal brains and misfunctioning brains.

Because the electrical activity was similar, this could lead to the study of diseases such as epilepsy, autism and the vast host of diseases which are thought to occur due to abnormal electrical signalling within the brain.

However, there are some pitfalls.

Just because the electrical activity is similar to that of a premature baby it does not mean it is the same. Given that these organoids are merely model of the foetal brain, any results or hypothesis we generate may be instantly invalid.

Proving that the lab-grown mini brains are the same as human foetus brains will also be a mammoth task: very little is known about utero baby brains and how they are wired. These mini brains could be missing key components that we have not yet even discovered.

So, we do not know for certain whether these brains match premature baby brains at a molecular or cellular level.

Consciousness Many scientists believe that conscious begins 24 to 28 weeks post fertilisation due to the fact that this is when the thalamo-cortical complex is developed enough to be able to supposedly generate consciousness. Furthermore, this is also when reflex reactions to harmful stimuli start occurring.

This raises the ethical quandary – are these organoids conscious? We can’t really say for sure – we cannot just measure for consciousness. Muotri’s lab is planning on seeing if these mini brains mature further and function as a normal cortex by connecting them to organoids of other body parts to see if it functions correctly.

He would consider halting the project if evidence that the organoids had become self-aware should arise, but right now they are very primitive. “It’s a very grey zone in this stage, and I don’t think anyone has a clear view of the potential of this”.

Cutting-edge research such as this often divides public opinion. The future rewards may be great but is there a hidden cost? Research using cerebral organoids has the potential to answer so many questions about the development of the human brain and – as lab-grown brains become increasingly complex – consciousness and what it means to be human. Do you think we should be conducting this research?

Bibliography Nature. 2018. Lab-grown ‘mini brains’ produce electrical patterns that resemble those of premature babies. [ONLINE] Available at https://www.nature.com/articles/d41586-018-07402-0. [Accessed 17 January 2019].