With more than 100 billion neurons and 200 billion cells, “the human brain,” Professor Kwanghun Chung explained to Interesting technique, “is one of the most complex systems in the universe.”
With each subsequent development in thinking, the brain becomes more and more complex. Each neuron forms tens of thousands of unique functional connections with other neurons. And of course no two brains are the same. Oh, and brains are plastic, they change.
Important steps have been taken to crack the brain, even if it looks more like slices, to take a picture of it. However, due to its complexity, neuroscience has not been able to penetrate an ‘intact’ brain. Until now. A team from MIT just did it.
Kwanghun Chung, associate professor at the Picower Institute for Learning and Memory, the Departments of Chemical Engineering and Brain and Cognitive Sciences, and the Institute for Medical Engineering and Science at MIT, said the human brain has historically been studied using two main technologies :
“Non-invasive in vivo imaging technologies, such as MRI, and light microscopy combined with molecular labeling methods, such as immunohistology.”
However, both technologies are inherently flawed, so in order to map the brain, Chung and his team of innovators had to update the technology.
Mapping the brain to understand brain function and dysfunction
In addition to billions of cells and neurons, scientists estimate that there are thousands of different types of neuronal cells in the human brain.
“To understand brain function and dysfunction,” Chung said, “we need to know how these cells are organized in three dimensions and how they are connected to each other.”
“Preserving and extracting this 3D information requires intact 3D tissues.”
However, until now it has not been possible to image the brain at subcellular resolution without first sectioning the brain.
“Human brains are too large to be imaged in their entirety using optical imaging techniques,” Chung continued.
But slicing an entire hemisphere of the brain can not only damage the tissue, but can also take months because “the slices have to be very, very thin.”
That posed a first challenge, or the opportunity to innovate the technology.
Entire hemispheres of the human brain have been mapped
MIT created a “technology pipeline,” a series of data processing elements, that successfully captured entire hemispheres in two donated brains, one of which had Alzheimer’s disease.
They produced three technologies that, according to Chung, “potentially” can fully map the human brain.
They haven’t yet imaged the entire human brain, but they “performed holistic imaging of human brain tissues at multiple resolutions, from single synapses to entire hemispheres.”
From “vast landscapes of thousands of neurons” to “diverse forests of calls, each in individual detail” to “tufts of subcellular structures nestled among extracellular molecules,” never before has such a detailed picture of the brain been produced. Look:
MIT has innovated not one technology, but three
Professor Chung called on three “particularly talented young scientists” who are also recognized as co-lead authors of the paper just published in Science because each produced three major innovations to achieve this feat in neuroscience.
Ji Wang created the ‘megatome’ that severs intact human brain hemispheres without damaging the tissue. Previously it took months to cut through a hemisphere of the brain, but she improved the design of these types of vibratome cutters so that no anatomical information was lost.
Once the disk itself was viable, the next step required an expert chemist, Juhyuk Park. He developed “mELAST,” a technology that “makes each slice clear, flexible, durable, extensible, and labelable quickly, evenly, and repeatedly.”
By making the slicer itself, Megatome, more efficient, they achieved the ability to take thicker ‘slices’ of the brain. But that wouldn’t have been possible without mELAST, because these technologies work together. MELAST is a hydrogel that makes the brain sample clear and indestructible and allows them to focus on areas of interest.
Once each plate was imaged, they needed computing power to bring that information to life in 3D. Webster Guan provided that system: UNSLICE.
It reconstructs 3D images of individual plates back to the intact brain with restored information about cell connectivity “down to the precise alignment of individual blood vessels and neural axons,” as explained in a press release.
The technological pipeline opens new doors for studying brain pathology
The study presents the robust capabilities of the breakthrough technology pipeline. This series of innovations allows neuroscientists to take a global view of a hemisphere, zoom in to the subcellular level, map the brain and understand brain pathology like never before.
Neuroscience can now fully image entire hemispheres of the human brain; they have updated the technology. Thanks MIT. They were able to study Alzheimer’s disease in new, stunning detail, pinpointing the location of most of the neuron loss in the brain. Thanks again.
And even better, bonus: the technology can be used on other fabrics.
They have just published their research showcasing their groundbreaking ‘series of innovations’ Science.
ABOUT THE EDITORIAL
Maria Mocerino Originally from LA, Maria Mocerino has been published in Business Insider, The Irish Examiner, The Rogue Mag, Chacruna Institute for Psychedelic Plant Medicines and now Interesting Engineering.