With more than 100 billion neurons and 200 billion cells, the “human brain” explained Professor Kwanghun Chung Interesting engineering, “is one of the most complex systems in the universe.”
With each further development of 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. And brains are plastic, they change.
Significant steps have been taken to crack it, although it’s more like a cut open the brain to take a picture of it. However, due to its complexity, neuroscience has not been able to get into the “intact” brain. Until now. A team from MIT just did it.
Kwanghun Chung, an associate professor in 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 that historically the human brain has 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.
Brain mapping to understand brain function and dysfunction
In addition to the billions of cells and neurons, scientists estimate that there are thousands of different types of neuron 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 connect.”
“Preserving and extracting this 3D information requires intact 3D tissues.”
Until now, however, it has not been possible to image the brain at subcellular resolution without first dissecting the brain.
“Human brains are too large to be visualized with optical imaging techniques in their entirety,” Chung continued.
But slicing an entire cerebral hemisphere can not only damage the tissue, it can take months because “the slices have to be very, very thin.”
This presented an initial challenge or chance to innovate the technology.
Entire hemispheres in the human brain have been mapped
MIT created a “technology channel,” a set of data processing elements that successfully captured the full hemispheres of two donated brains, one of which had Alzheimer’s disease.
They have created three technologies that can “potentially” fully map the human brain, according to Chung.
They have not yet captured the entire human brain, but have “performed holistic multi-resolution imaging of human brain tissues from individual synapses to entire cerebral hemispheres.”
From “vast landscapes of thousands of neurons” to “diverse forests of calls, each in individual detail” to “tuds of subcellular structures nestled between extracellular molecules,” such a detailed picture of the brain has never before been created. Look:
MIT did not innovate ONE technology, but three
Professor Chung invited three “particularly talented young scientists” who were also accredited as co-authors of the paper, which was just published in Science as they each brought three major innovations to achieve this feat in neuroscience.
Ji Wang created a “Megatom” that slices intact hemispheres of the human brain without damaging the tissue. It used to take months to dissect a cerebral hemisphere, but she improved the design of this kind of vibratome so that no anatomical information was lost in the process.
Once the cut was viable on its own, the next step required an expert chemist, Juhyuk Park. He developed the “mELAST” technology, which makes “each wafer clear, flexible, durable, expandable and quickly, evenly and repeatedly marked”.
By streamlining the slicer itself, the Megatome, they were able to remove thicker “plates” from the brain. But this would not be possible without mELAST, because these technologies work together. MELAST is a hydrogel that makes the brain sample clear and indestructible and also allows them to focus on areas of interest.
Once each plate was rendered, they needed the computing power to bring that information to 3D life. Webster Guan provided this system: UNSLICE.
It reconstructs 3D images from individual slabs back into the intact brain with recovered information about cellular connectivity “down to the precise alignment of individual blood vessels and nerve axons,” as explained in the press release.
The technology pipeline opens new doors to the study of brain pathology
The study presents the robust capacities of a breakthrough technological pipeline. This suite of innovations allows neuroscientists to take a global image of a hemisphere, zoom in on the subcellular level, map the brain, and understand brain pathology like never before.
Neuroscience can now fully image the entire hemispheres of the human brain; they updated the technology. Thanks MIT. They were able to study Alzheimer’s disease in new, stunning detail, able to pinpoint where the majority of neurons were lost in the brain. Thanks again.
And an even better bonus: the technology can be applied to other tissues.
They have just published their study which represents their breakthrough “innovation suite” in 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.