Organoids: The Test-Tube Brain
The image of a human brain floating in some glowing viscous liquid has always been a favorite for decorating the laboratories of mad scientists and cackling witches. What mad scientists and witches do with human brains is anyone’s guess, but their goals likely don’t align with the group of scientists who have nearly made this trope a reality.
Researchers at the Institute of Molecular Biotechnology in Vienna have recently developed a technique for studying various brain ailments that mimics this science-fiction trope to a degree, using stem cells to grow miniaturized brains they call organoids. These organoids, which each measure no more than 3-4 millimeters in diameter, are grown in a nutrient-rich liquid that simulates the womb, giving them a chance to observe the analogue as it grows. Admittedly, while these organoids aren’t nearly as complex as a completely developed human brain, they have developed many of the same partitions as the real thing, including the dorsal cortex, ventral forebrain, and even hints of optic nerve.
While the very notion of growing tiny brains in a test tube is intriguing enough, the research possibilities that stem from this are even more exciting. Not only do these diminutive brains contain incredibly close analogues to their larger counterparts, they have been proven to react similarly to degenerative conditions. Jürgen Knoblich, one of the creators of the original organoid, and Madeline Lancaster, the first to publish on the subject, teamed up to purposefully recreate the neurological disease microcephaly, a disease that prevents brain cells from dividing properly. As with brains affected by the disease, this engineered organoid ended up significantly smaller than the healthy control group. The disease ran its course as it would in a developing fetus, giving scientists a never-before-seen glimpse into the first stages of this neurological disorder. This kind of first-hand glance at the way these diseases develop gives a more detailed view than the current method of isolating cell clusters, and it could potentially eliminate the need for animal testing, as well. Studying the effects of a disease is one thing, but watching it run its course during early neurological development is another thing entirely. Researchers believe that this may allow them to identify and potentially even cure the genetic root of such diseases.
That said, it’s important to curb enthusiasm with reality. While this development is certainly groundbreaking, it’s not magic. The complexity of the human brain is far too great to replicate in a laboratory (at least for now), so it’s likely that these organoids will be as far as we’re able to go for some time. However, the potential for development in other directions is still entirely possible. We’ve already grown pituitary glands, eyes, and livers. I’d be very surprised if these sorts of developments stopped with the organoid. If anything, I’d expect these findings to fuel the fire even higher.
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