“At what point can a mini-brain with brain activity be considered conscious?”

Alysson Muotri, a neuroscientist at the University of California, San Diego, and his team have improved the techniques for obtaining brain organoids and have discovered that, after a period of development, the organoids spontaneously produce electrical activity similar to that observed in the brain of premature babies.

With some 86,000 million neurons, the brain is a particularly difficult organ to study. One solution is to investigate a simplified system with fewer neurons. In 2013, Madeline Lancaster’s team at the Institute of Molecular Biotechnology in Vienna produced mini-brains— also known as cerebral organoids — in the laboratory from human stem cells. Although these mini-brains are very useful to researchers, electrical activity has never been observed in them until now.  The cerebral organoids provide an opportunity to study such issues. The size of a pea, they are obtained from human pluripotent stem cells. If placed in an environment that reproduces the conditions in which the brain develops, these cells differentiate and form neurons that self-organize into a three-dimensional structure. This results in a smaller and simplified version of the human cortex (the brain region involved in cognition and interpretation of sensory information). Despite this breakthrough, the organoids remain rudimentary models and are far from representing the complexity of the human brain. The current work also raises ethical issues: At what point can a mini-brain with brain activity be considered conscious? We still lack a great deal of knowledge about the brain to answer this thorny question (See HERE).

Bioethical comment of mini brains findings

Our Observatory published a special report titled Neuroscience. New experiments with brain rekindle the bioethical debate. We quote from our study this phrase, […]neuroscience in general and studies with brain tissue, organoids or chimeras in particular, raise numerous serious ethical questions that must be addressed before continuing with this type of research. In our opinion, this area of medical research is one of those that pose the greatest bioethical problems[…]