For the first time, an almost fully formed human brain has been grown in the lab, according to scientists from Ohio State University.
'It not only looks like the developing brain, its diverse cell types express nearly all genes like a brain,' said Professor Rene Anand, who presented the research at the Military Health System Research Symposium in Florida last Tuesday. 'This brain model... gives us better and more relevant options to test and develop therapeutics other than rodents.'
The brain is comparable to that of a five-week-old fetus and it is hoped that it could be used to study neurological diseases, such as post-traumatic stress disorder, autism and Alzheimer's disease, and to test new drugs.
The research team say the brain has the beginnings of a spinal cord and an eye, and has around 99 percent of the fetal brain's genes and cell types – such as neurons, astrocytes and microglia – but it is not conscious. It is around the size of a pencil eraser, and currently does not have a vascular system.
The brain could be used as an alternative disease model, instead of computer models, cells, and mice, and could help understand how a genetic predisposition for a disease will affect the brains development.
As the technique for creating the brain is currently being patented, the researchers have not made full details of the methods available. However, it is known that adult skin cells underwent genetic modification to become pluripotent stem cells, from which they were influenced to form different brain regions.
The research has not yet been peer reviewed and published, and other scientists were hesitant to draw conclusions from what has been announced so far.
Professor Zameel Cader, consultant neurologist at John Radcliffe Hospital in Oxford, UK, told The Guardian, 'When someone makes such an extraordinary claim as this, you have to be cautious until they are willing to reveal their data'.
Other organs have previously been successfully grown from pluripotent cells, but the brain is considered more challenging because it is the most complex organ. A previous attempt at growing a brain in the lab created a partial brain equivalent to a nine-week-old fetus, which was used to investigate the neurological condition microcephaly. However this was only a 'cerebral organoid' which lacked some of the structure and function of an entire brain.
The Ohio State University team are now using their brain to create models of Alzheimer's disease, Parkinson's disease and autism.