Neural mapping

Google Research is driving progress toward precisely mapping the connections between every cell in the brain.

Google Research is driving progress toward precisely mapping the connections between every cell in the brain.

What is connectomics?

The human brain is perhaps the most computationally complex machine in existence, consisting of networks of billions of cells. Researchers currently don’t understand the full picture of how glitches in its network machinery contribute to mental illnesses and other diseases, such as dementia. However, the emerging connectomics field, which aims to precisely map the connections between every cell in the brain, could help solve that problem.

The Connectomics team at Google Research has played a key role in advancing the connectonomics field by developing new technologies that have accelerated scientific progress. These technologies enabled us to map parts of the fruit fly and mouse brains, and could one day help us better understand how the human brain works and how to treat brain diseases. The timeline and chart below demonstrate how connectomics has evolved since the 1970s.

Connectomics milestones

Connectomics milestones

1986: Roundworm connectome

In 1986, a team of researchers successfully completed the C. elegans roundworm’s connectome, which contains 302 neurons. This effort was completed over 16 years, and required researchers to use markers to trace the paths of the roundworm’s neurons on enlarged photographs.

2020: Fruit fly hemibrain

In 2020, Google Research and collaborators released the fruit fly "hemibrain" connectome, an online database providing the morphological structure and synaptic connectivity of roughly half of the brain of a fruit fly. This database and its visualization has reframed the way that neural circuits are studied and understood in the fly brain. The project used machine learning tools developed at Google to map about 125,000 neurons an order of magnitude faster than would have been possible without these tools.

2021: The first human connectome

In 2021, Google Research and collaborators released the H01 dataset, a 1.4 petabyte rendering of a small sample of human brain tissue. This was the first-ever human connectome project, which used tools and software developed at Google Research to map a small part (roughly one cubic millimeter) of the human brain — all easily accessible with the Neuroglancer browser interface. The project unveiled preliminary insights into the structure of the human cortex.

2023: Mapping the mouse brain

In September 2023, Google Research and collaborators announced the launch of the largest connectome project yet: mapping the connectome of 2-3 percent of the mouse brain over the next five years. The project will specifically target the hippocampal region, which is responsible for encoding memories, attention and spatial navigation. The initiative, supported by the National Institutes of Health, is part of a program that aims to create a whole mouse brain connectome.

This chart and timeline below shows how connectomics has evolved since the 1970s.

Collaborations with the research community

Collaborations with the research community

A photo of gerry Rubin. Photo credit: Matt Staley, HHMI’s Janelia Research Campus

A photo of Gerry Rubin. Photo credit: Matt Staley, HHMI’s Janelia Research Campus

More than a "mass of spaghetti"

Gerry Rubin, director of the Howard Hughes Medical Institute's Janelia Research Campus, and a team of researchers constructed the fruit fly connectome, revolutionizing brain mapping.

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Gwyneth Card headshot

A photo of Gwyneth Card. Photo credit: John Abbott, Columbia's Zuckerman Institute

Escaping danger

Gwyneth Card, a neuroscientist who leads a lab at Columbia University's Zuckerman Institute, researches how insect brains are wired to help them flee from predators.

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Jeff Lichtman

A photo of Jeff Lichtman.

The mouse connectome moonshot

Jeff Lichtman, a neuroscientist who leads the Lichtman Lab at Harvard University, is working towards mapping the first whole mammalian brain.

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