Researchers from Harvard University and Google published the largest synaptic-resolution and 3D reconstruction of a piece of human brain to date.
The cubic millimetre of brain tissue is about half the size of a grain of rice but contains 57,000 cells, 230mm of blood vessels, and 150 million synapses.
The resulting digital reconstruction amounts to 1,400 terabytes of data. It is described in a new paper in the journal Science.
“The word ‘fragment’ is ironic,” says Jeff Lichtman, a professor of molecular and cellular biology at Harvard University, who led the research.
“A terabyte is, for most people, gigantic, yet a fragment of a human brain – just a miniscule, teeny-weeny little bit of human brain – is still thousands of terabytes.”
The research is the result of a nearly 10-year collaboration between Lichtman’s team and scientists at Google Research, who combine Lichtman’s electron microscopy imaging with AI algorithms to colour-code and reconstruct mammal brains in 3 dimensions.
Their ultimate goal is to create a high-resolution map of a whole mouse brain.
This field of research studies the “connectome” which is defined as the “complete, point-to-point spatial connectivity of neural pathways in the brain”.
Creating a comprehensive catalogue of brain structure, down to individual cells, would help provide new insights into brain function and disease.
“Given the enormous investment put into this project, it was important to present the results in a way that anybody else can now go and benefit from,” says co-author Viren Jain, a research scientist at Google Research.
The authors are: “sharing all of the data in an online resource and also providing tools for analysis and proofreading.”
Next up is the mouse hippocampal formation, which is important to neuroscience for its role in memory and neurological disease.