A near-complete human brain comparable with that of a five-week-old foetus has been grown in a laboratory dish.
The brain ”organoid” was created from reprogrammed skin cells and is about the size of a pencil eraser.
Scientists hope the lumpy mass of functioning nerve cells and fibres will prove to be a valuable research tool for non-animal testing of new drugs and investigating brain disorders.
As well as neurons and their signal-carrying projections the “brain” also contains support and immune cells.
It has 99% of the genes present in the fetal brain, a rudimentary spinal cord, and even the beginnings of an “eye”.
Lead researcher Professor Rene Anand, from Ohio State University, said: “We’ve struggled for a long time trying to solve complex brain disease problems.
The power of this brain model bodes very well for human health because it gives us better and more relevant options to test and develop therapeutics other than rodents.”
Already the scientists have gone on to create brain organoid models of Alzheimer’s and Parkinson’s disease, and autism, in a dish.
With the addition of a blood circulation, which is currently lacking, they also hope to use the model to study stroke therapies.