Devangshu Datta: Grey matter and beyond

Scientists have grown a human brain in the laboratory. This might change the way diseases are studied and diagnosed

A few days ago, a team of scientists led by Dr Rene Anand of Ohio State University, claimed to have made a big breakthrough. Dr Anand says his team has successfully grown a model human brain in the laboratory. The claim is controversial because the process has not yet been peer-reviewed and data has not been released for other scientists to judge the work.

The research was presented at the American Military Health System Research Symposium in Florida. The brain is said to be about the size attained by a five-week foetus (about the size of a pencil eraser, or about four-six millimetres in diameter).

Dr Anand says the delay in releasing data and writing a paper for peer-review is because there are patents pending on the methods used to grow the 'organoid' or mini-organ. He and his colleague, Susan B McKay have set up a company, NeurXstem, which is presumably hoping to commercially exploit the intellectual property from this research.

It is claimed that human skin cells were collected from an adult and then converted into so-called pluripotent cells that is, stem cells, which can turn into any organic tissue. The converted cells were then grown in a 'specialised environment' that induced them to grow into brain cells of many different types. The techniques used to induce differentiation may be part of the intellectual property being patented.

It took about 15 weeks for the lab cells to reach this (five-week foetus) stage of development. According to the press release, it would take a more sophisticated network of blood vessels and an artificial heart to enable the brain to grow much further.

Researchers in biological labs often grow models of organs in order to get a deeper understanding of the mode of functioning, and also sometimes to replace defective organs. Eyes, livers, bladders, blood vessels etc have all been grown in the lab. But the brain is of higher complexity.

Earlier attempts to grow brains have yielded brain organoids with lower complexity. In 2013, researchers at the Institute of Molecular Biotechnology in Vienna, for example, used stem cells directly to grow a brain, which was in fact, larger than the Ohio experiment. But that Austrian brain organoid had much more immature structures.

This brain is small. But it has similar complexity to a full-sized brain, including 99 per cent of the diverse cell types found in an adult brain. The structures include the beginnings of a spinal cord, cortex, midbrain, brain stem, 'signal circuitry' and retina. The cells include neurons, axons and dendrites, which are essential to the body's signalling system. Dr Anand says speculatively, that it may be possible to develop the "remaining one per cent" of brain cells if the process is continued for a few more weeks.

The organoid has no awareness. It is not connected to any sensory input organs. So it doesn't receive any inputs. In this way, all ethical issues involving consciousness and cognition are avoided. Initially, this organoid will be used to study stresses caused by war, such as post-traumatic stress disorder, and also the impact of traumatic brain injuries. This is why this research was unveiled at the military health symposium.

Assuming the claims about the new technology are validated and this is patented, the technology could be licensed out to study a vast range of neurological diseases and conditions. For example, Parkinson's disease, Alzheimer's, schizophrenia, autism etc could all be studied in detail. Also, the potential effects and side-effects of drugs could be tested. If a blood circulation system for this can be devised, it would be possible to study an even wider range of conditions, such as strokes.

It would also be possible to study the effect of environmental toxins on foetal development in great detail by monitoring the expression of every gene and carefully varying the chemicals in the environment.

The technique even has the potential to change the way in which medical diagnosis is done. A lab could take a skin sample from a patient and grow a brain organoid that possessed all the patient's genes, investigate things in detail and offer a completely personalised diagnosis.

The possibilities are obviously, exciting. However, this sort of claim always has to be treated with caution until it has been peer-reviewed and the experimental results have been reproduced.