A group of scientists, including several at Harvard, have dived deeper into the mammalian brain than ever before by categorizing and mapping at the molecular level all of its thousands of different cell types.
The researchers reported their work in Nature, through a series of 10 papers — six with Harvard affiliations. It’s part of the National Institutes of Health’s Brain Research Through Advancing Innovative Neurotechnologies initiative, which so far has focused on mice; future phases will shift to humans and other primates.
Mammal brains house billions of cells, each defined by the genes they express. This complexity is why true understanding of many brain functions, including molecular mechanisms that underlie neurological diseases, remains so elusive.
To create the first molecularly defined cell atlas of the whole mouse brain, a team led by Harvard’s Xiaowei Zhuang identified and spatially mapped thousands of unique cell types, most of which had never previously been characterized.
“We identified 5,000 transcriptionally distinct cell populations,” said Zhuang, the David B. Arnold Professor of Science and a Howard Hughes medical investigator. “Suffice it to say that the level of diversity we identified is really extraordinary.”
The brain-wide atlas of cell types cataloging cells, their distribution, and interactions could serve as a starting point for scientists studying certain brain functions or diseases. Someday the basic outlines of the atlas could be applied to the human brain, 1,000 times larger than the mouse brain.
“It gives me real excitement to see things that were not visible before. I am also thrilled when our technology is used by so many labs,” said Zhuang, referring to Multiplexed Error-Robust Fluorescence in situ Hybridization (MERFISH), a genome-scale imaging technology developed in her lab.
