With over 85 billion neurons that have an average of 10,000 connections to other neurons, mapping the brain is practically impossible. More like a pipedream for neuroscience.
And the brain gets increasingly more and more complex with every development in thought thereafter. Different kinds of neurons, neurotransmitters, sensory inputs, and of course, no two brains are alike. Oh, and brains are plastic, they change.
Significant steps have been made to crack though it’s more like “slice” open the brain to snap a picture of it, even its circuitry. However, due to its complexity, neuroscience hasn’t been able to get inside an “intact” brain. Until now.
A team from MIT just did it and published their study in Science.
They created a “technology pipeline” that successfully captured full hemispheres in two donated brains, one of which had Alzheimer’s.
Whole hemispheres in the human brain has been mapped
A technology pipeline is a set of data processing elements that feed into one another. In this case, they produced three technologies that can “potentially,” according to Kwanghun Chung, senior and corresponding author, map the human brain fully.
They didn’t capture the whole brain as of yet, but they “performed holistic imaging of human brain tissues at multiple resolutions from single synapses to whole brain hemispheres.”
From “sweeping landscapes of thousands of neurons” to “diverse forests of calls each in individual details” to “tufts of subcellular structures nestled among extracellular molecules,” never before has such a detailed picture of the brain been produced. Take a look:
Mapping the brain at subcellular resolution would provide unprecedented insights into “the underlying mechanisms of brain cognition and brain disease pathogenesis,” according to another study. So this suite of integrated technologies stands to impact how we study these diseases.
Before now, imaging the brain “at subcellular resolution” wasn’t possible without slicing the brain first because of its thickness. That presented an initial challenge, or the chance to innovate the tool used to slice the brain.
MIT didn’t innovate ONE technology but three
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, Kwanghun Chung called upon three “especially talented young scientists” also co-lead authors of the paper because they each produced three major innovations to achieve this feat in neuroscience.
Ji Wang created the “Megatome” that slices intact human brain hemispheres without damaging the tissue. Previously, it took months to slice a hemisphere of the brain, but she improved the design of this kind of vibratome slicer so that no anatomical information was lost in the process.
Once the slice itself was viable, the next step required an expert chemist, Juhyuk Park. He developed “mELAST,” a technology that makes “each slice clear, flexible, durable, expandable, and quickly, evenly and repeatedly labelable.”
By making the slicer itself, Megatome, more efficient, they achieved taking thicker “slabs” of the brain. But that wouldn’t have been possible without mELAST, as these technologies work together. MELAST is a hydrogel that makes the brain sample clear and indestructible and also allows them to zero in on areas of interest.
At that point, once each slab was imaged, they needed computational power to bring that information to 3D life. Webster Guan provided that system: UNSLICE. It “reunifies the slabs to reconstruct each hemisphere in full 3D down to the precise alignment of individual blood vessels and neural axons,” as explained in a press release.
The technological pipeline opens new doors to study brain pathology
The study presents the robust capacities of the groundbreaking pipeline of innovations. Not only does this package enable neuroscientists to take a global picture of a hemisphere but also zoom in to the subcellular level and map the brain like never before, due to its sheer complexity.
For disease research, the pipeline stands to open new doors to understanding brain pathology. The team imaged an Alzheimer’s brain because Chung collaborates with an Alzheimer’s researcher, co-author Matthew Frosch. They were able to study the disease to a new detail, specifically where the majority of neuron loss concentrates itself in the brain.
“This pipeline allows us to have almost unlimited access to the tissue,” Chung said.
“We can always go back and look at something new.”
They don’t seek to present any conclusions about the disease at this point but rather the capacity to analyze the brain to this degree of depth. Neuroscience can now fully image whole hemispheres of the human brain; they updated the technology. Thanks again MIT.
And even better, bonus: the technology can be used on other tissues.
They just published their study that presents their groundbreaking “suite of innovations” in Science.
ABOUT THE EDITOR
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.
