August 29, 2013
Austrian Lab Grows Miniature Human Brains
Michael Harper for redOrbit.com - Your Universe Online
In the ongoing quest to better understand the human brain, scientists from the Austrian Academy of Sciences have been growing their own mini brains. These small collections of tissue aren’t capable of thought and are much smaller than a fully developed brain, but scientists say they’re still very valuable research tools.The brain matter began life as stem cells suspended in gel, which were then submerged into a solution of nutrients and oxygen. With so much more left to understand about the development of the brain, scientists say these small models could help them get to the bottom of neurological diseases and mental disorders. The models could also give doctors an insight into the way a fetus’ brain develops and could even provide them with a medium with which to test new drugs. The Austrian scientists’ work is now published in the journal Nature.
In this paper, the researchers describe a method wherein pluripotent stem cells are allowed to grow freely in a solution rather than be guided along a pattern. This means the stem cells’ growth very closely resembles the way that they naturally develop in the womb.
So far the scientists have seen the cells grow into distinct portions of the brain, including the cerebral cortex, the retina and, on occasion, the hippocampus. Dr. Jürgen Knoblich at the Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA) led the research and explains how his team was able to grow these “cerebral organoids.”
"We modified an established approach to generate so-called neuroectoderm, a cell layer from which the nervous system derives,” said Dr. Knoblich in a statement. “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."
Though formed, the brains aren’t any larger than 4 millimeters, or about 0.1-inch, when they reach their full size. They’ve survived in their current form for over a year, but without a blood supply, the “test tube” brains will not get any bigger. Blood carries oxygen and nutrients to the inside of the brain, promoting function and growth.
Knoblich is already putting his brain-growing technique to work and has partnered with neurologists from Edinburgh University to grow organoids which model the development of brains stricken with a disorder. So far they have modeled the developmental disease microcephaly — a condition which prevents the brain from growing to full size — and hope to learn how this disorder originates in hopes to one day catch it at its earliest stages.
"When I looked at the organoids derived from the microcephaly patient cells, the immediate thing I noticed was that [their] overall size was much smaller than the organoids derived from control, healthy cells," Madeline Lancaster, first author of the paper, told the Guardian.
"Ultimately we would like to move towards more common disorders like schizophrenia or autism,” said Knoblich, who is eager to begin observing the organoids. “They typically manifest themselves only in adults, but it has been shown that the underlying defects occur during the development of the brain."
New medicines could also be tested on the mini-brains, allowing doctors and researchers to move away from testing drugs on mice and other animals.