A squishy, fatty, beige-colored organ covered with grooves and ridges, the brain doesn\u2019t look all that impressive on the surface. <\/p>\n
But hidden underneath are up to 100 billion neurons and 100 trillion synapses\u2014the connections between neurons that form networks\u2014densely packed in a squishy three-pound organ that controls our thoughts, feelings, movement, memories, and sense of self.<\/p>\n
For the past two decades, scientists have carefully dissected the internal neural connections and workings of the brain by carefully chopping it up into paper-thin pieces. From there, they\u2019ve built multiple maps of the brain\u2019s cellular population, architecture, connections, and gene expression. Like charting the landscape of a new world, these maps have been consolidated into what amounts to a Google Maps for the brain. These atlases allow us to decipher brain function, bridging genetic expression to cell functions, network connections, and behavior. <\/p>\n
At least for rodents and other animals. Mapping the brain is incredibly difficult and time-consuming. A small chunk of a mouse\u2019s brain, when imaged at single-cell resolution, takes years to process, scan, and reconstruct into 3D computer models. Any trip-ups during the process ruins the product. Mapping the human brain, much larger in size, is far more difficult. <\/p>\n
This month, a team from MIT developed a \u201cholistic\u201d brain-mapping platform that captures the anatomy of large slices of the human brain with unprecedented resolution and speed, slashing a process that normally takes between a week and a month to a few days. <\/p>\n
They used the platform to image an Alzheimer\u2019s brain, after physically expanding brain tissues with a hydrogel. The automated system sliced, imaged, and automatically stitched the images together and found myriads of cellular changes and problems with neural connections, including inflammation. <\/p>\n