Maybe this will eventually be able to help improve the quality of left and right talk show hosts: for the first time ever, scientists say they’ve been able to grow “mini-brains in a laboratory— the first time the brain tissue has been been created by humans in three dimensions. This has enormous medical and scientific potential:
Scientists have grown the first mini human brains in a laboratory and say their success could lead to new levels of understanding about the way brains develop and what goes wrong in disorders like schizophrenia and autism.
Researchers based in Austria started with human stem cells and created a culture in the lab that allowed them to grow into so-called “cerebral organoids” – or mini brains – that consisted of several distinct brain regions.
It is the first time that scientists have managed to replicate the development of brain tissue in three dimensions.
Using the organoids, the scientists were then able to produce a biological model of how a rare brain condition called microcephaly develops – suggesting the same technique could in future be used to model disorders like autism or schizophrenia that affect millions of people around the world.
Yes, they’ll use brains to study medical disorders (as opposed to the ideological disorders of the partisan talk show hosts):
“This study offers the promise of a major new tool for understanding the causes of major developmental disorders of the brain … as well as testing possible treatments,” said Paul Matthews, a professor of clinical neuroscience at Imperial College London, who was not involved in the research but was impressed with its results.
Zameel Cader, a consultant neurologist at Britain’s John Radcliffe Hospital in Oxford, described the work as “fascinating and exciting”. He said it extended the possibility of stem cell technologies for understanding brain development and disease mechanisms – and for discovering new drugs.
Although it starts as relatively simple tissue, the human brain swiftly develops into the most complex known natural structure, and scientists are largely in the dark about how that happens.
This makes it extremely difficult for researchers to gain an understanding of what might be going wrong in – and therefore how to treat – many common disorders of the brain such as depression, schizophrenia and autism.
The scientists at the Institute of Molecular Biotechnology (IMBA) of the Austrian Academy of Sciences (OeAW), led by Dr. Jürgen Knoblich, fine-tuned growth conditions and provided a conducive environment.
Cues from the stem cells guided the development towards different interdependent brain tissues. The scientists were also able to model the development of a human neuronal disorder and identify its origin.
Starting with established human embryonic stem cell lines and induced pluripotent stem (iPS) cells, the group identified growth conditions that aided the differentiation of the stem cells into several brain tissues. While using media for neuronal induction and differentiation, the group was able to avoid the use of patterning growth factor conditions, which are usually applied in order to generate specific cell identities from stem cells. Dr. Knoblich explains the new method: “We modified an established approach to generate so-called neuroectoderm, a cell layer from which the nervous system derives. Fragments of this tissue were then maintained in a 3D-culture and embedded in droplets of a specific gel that provided a scaffold for complex tissue growth. In order to enhance nutrient absorption, we later transferred the gel droplets to a spinning bioreactor. Within three to four weeks defined brain regions were formed.”
After only 15 — 20 days, so-called “cerebral organoids” formed which consisted of continuous tissue (neuroepithelia) surrounding a fluid-filled cavity that was reminiscent of a cerebral ventricle. After 20 — 30 days, defined brain regions, including a cerebral cortex, retina, meninges as well as choroid plexus, developed. After two months, the mini brains reached a maximum size, but they could survive indefinitely (currently up to 10 months) in the spinning bioreactor. Further growth, however, was not achieved, most likely due to the lack of a circulation system and hence a lack of nutrients and oxygen at the core of the mini brains.
The new method also offers great potential for establishing model systems for human brain disorders. Such models are urgently needed, as the commonly used animal models are of considerably lower complexity, and often do not adequately recapitulate the human disease.
Knoblich’s group has now demonstrated that the mini brains offer great potential as a human model system by analysing the onset of microcephaly, a human genetic disorder in which brain size is significantly reduced. By generating iPS cells from skin tissue of a microcephaly patient, the scientists were able to grow mini brains affected by this disorder. As expected, the patient derived organoids grew to a lesser size.
Further analysis led to a surprising finding: while the neuroepithilial tissue was smaller than in mini brains unaffected by the disorder, increased neuronal outgrowth could be observed. This lead to the hypothesis that, during brain development of patients with microcephaly, the neural differentiation happens prematurely at the expense of stem and progenitor cells which would otherwise contribute to a more pronounced growth in brain size. Further experiments also revealed that a change in the direction in which the stem cells divide might be causal for the disorder.
Joe Gandelman is a former fulltime journalist who freelanced in India, Spain, Bangladesh and Cypress writing for publications such as the Christian Science Monitor and Newsweek. He also did radio reports from Madrid for NPR’s All Things Considered. He has worked on two U.S. newspapers and quit the news biz in 1990 to go into entertainment. He also has written for The Week and several online publications, did a column for Cagle Cartoons Syndicate and has appeared on CNN.