Biology

Google and Harvard map brain connections in unprecedented detail

Google and Harvard map brain c...
A color-coded map of around 4,000 incoming axons connecting to just one neuron
A color-coded map of around 4,000 incoming axons connecting to just one neuron
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A color-coded map of around 4,000 incoming axons connecting to just one neuron
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A color-coded map of around 4,000 incoming axons connecting to just one neuron
Left: a small section of the dataset. Right: A subgraph of neurons, highlighting excitatory neurons in green and inhibitory neurons in red.
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Left: a small section of the dataset. Right: A subgraph of neurons, highlighting excitatory neurons in green and inhibitory neurons in red.

A browsable 3D map of just one millionth of the cerebral cortex has been created using 225 million images and a whopping 1.4 petabytes of data.

The human brain is the most ridiculously complex computer that’s ever existed, and mapping this dense tangle of neurons, synapses and other cells is nigh on impossible. But engineers at Google and Harvard have given it the best shot yet, producing a browsable, searchable 3D map of a small section of human cerebral cortex.

With about 86 billion neurons connecting via 100 trillion synapses, it’s a Herculean task to figure out exactly what each of them does and how those connections form the basis of thought, emotion, memory, behavior and consciousness. Daunting as it may be, though, teams of scientists around the world are rolling up their sleeves and trying to build a wiring diagram for the human brain – a so-called “connectome.”

Last year, researchers at Google and the Howard Hughes Medical Institute paved the way with a fruit fly brain connectome that encompassed about half of the insect’s full brain. Now, Google and the Lichtman Lab at Harvard have released a similar model of a tiny section of human brain.

The researchers started with a sample taken from the temporal lobe of a human cerebral cortex, measuring just 1 mm3. This was stained for visual clarity, coated in resin to preserve it, and then cut into about 5,300 slices each about 30 nanometers (nm) thick. These were then imaged using a scanning electron microscope, with a resolution down to 4 nm. That created 225 million two-dimensional images, which were then stitched back together into one 3D volume.

Machine learning algorithms scanned the sample to identify the different cells and structures within. After a few passes by different automated systems, human eyes “proofread” some of the cells to ensure the algorithms were correctly identifying them.

The end result, which Google calls the H01 dataset, is one of the most comprehensive maps of the human brain ever compiled. It contains 50,000 cells and 130 million synapses, as well as smaller segments of the cells such axons, dendrites, myelin and cilia. But perhaps the most stunning statistic is that the whole thing takes up 1.4 petabytes of data – that’s more than a million gigabytes.

Left: a small section of the dataset. Right: A subgraph of neurons, highlighting excitatory neurons in green and inhibitory neurons in red.
Left: a small section of the dataset. Right: A subgraph of neurons, highlighting excitatory neurons in green and inhibitory neurons in red.

And that’s just a tiny fragment of the whole thing – Google says the sample is just one millionth of the volume of the full human brain. Clearly it’s going to take a huge amount of work to scale that up, as will finding a way to store the immense data load and develop a way to organize and access it in a useful way.

While the team begins tackling those problems, the H01 dataset is now available online for researchers and curious onlookers to explore. A companion pre-print paper describing the work is also available on bioRxiv.

A zooming tour through the different layers can be seen in the video below.

H01 Volume: Aligned Data & Segmentation

Source: Google AI Blog

9 comments
9 comments
ChairmanLMAO
Pretty soon these will be searcheable online just like google earth, moon and mars. Can't wait so we can check normal brain vs. political brain.
Riaanh
As if the billions of neurons and trillions of synapses is not enough, on top of this complexity is the quantum effects which is unavoidable at molecular and even cell scale. -- The bottom line is, your brain is a quantum computer.

http://www.bbc.com/earth/story/20170215-the-strange-link-between-the-human-mind-and-quantum-physics?ocid=twert
paleochocolate
once it's uploaded in it's entirety, I think an AI advanced enough will be able to compress the file greatly. Pretty sure there is a lot of unnecessary data in there.
1stClassOPP
Mind blowing intricacies. Recently I observed clouds of tiny gnats and tried to wrap my head around the fact that each one of those millions have a brain that can decide to fly or not and go where they want. They live for about seven days. Amazing!
Kevin Ritchey
By doing this, it will finally be available to see what happens when disease creates changes.
stevendkaplan
So if what they’ve gathered is just 1 millionth of a full human brain that means that a full map of the human brain would take roughly 1.4 zettabytes of info to store. That’s more than all the info currently circulating on the internet right now!
bothib
We can pause in our busy, whirlwind life and contemplate the wonders of evolution.
michael_dowling
If I upload a brain scan,can they use it to find my car keys?
michael_dowling
This mapping project is interesting,but what can be gleaned from it? You are looking at an almost infinite number of connections in the average brain,and every brain is unique.