Google is going to look inside the mouse brain, here’s why

Google to study mice brains

Researchers at Google recently mapped an extremely small part of the human brain (1 cubic millimetre of human brain tissue, to be exact). According to Google, it is the "largest, most detailed map of the human brain yet". After carefully observing the human brain at a high resolution, Google researchers got confounded at times, with several unexplained things like the wires inside the human brain wrapping into giant knots by themselves. To understand mammalian brains better and get the answers to several unexplained phenomena in the human brain, Google has decided to look inside the mouse brain.

Mapping the mouse brain: What answers does Google want?

Scientists at Google Research are now going to map the brains of mice, according to a blog post by Google. Their goal is to find answers to questions like “How are memories stored and retrieved? How do we recognize objects and faces? Why do we need so much sleep? And what goes wrong in Alzheimer’s and other brain diseases”?

Viren Jain, a Google Research scientist who’s part of the team, believes that the Google team not have the answers to these questions because they don’t have enough data to study the brain.

Human brain mapping: The challenges Google faces

As per Google, the human brain has “about 86 billion neurons connected to each other by more than 100 trillion synapses”. To image the human brain, Google founded the Connectonomics team at Google Research 10 years ago. A “connectome” is a Google-coined word for a map of neural connections.

Google’s challenge is that it has to do a nanometre mapping of the entire human brain connectome which would require “gathering and analyzing as much as a zettabyte of data (one billion terabytes). It is “beyond the current capabilities of existing technologies”, the estimated time going into hundreds of years, not to mention the billions of dollars that’ll go into the brain mapping project.

Why has Google chosen mice for brain mapping?

Researchers at Google don’t have the time or the technology for the human brain endeavour yet. That’s why the Google Connectomics team has partnered with universities like Harvard, Princeton and others to map the hippocampus of a mouse, which they believe to be the next best thing to a human brain.

The brain of a mouse looks very similar to a human brain, and that's one reason why mice brains are used to study disorders in the human brain. Another thing worth noting is that the hippocampus is about 2-3% of the mouse brain– allowing Google researchers to concentrate on a much smaller part–and is the part of the brain responsible for “encoding memories, attention and spatial navigation”.

Even when we consider that the mouse brain is 1000 times smaller than the human brain, mapping it remains an “immense technical challenge”, says Google.

As per Google, “The dataset from one mouse brain connectome at nanometer resolution could be the largest biological dataset ever collected, estimated at about 20,000-30,000 terabytes.”

If Google researchers in the Connectomics team are successful, it would be the first time scientists would have mapped part of a mammalian hippocampus. The mouse hippocampus is also the “largest-ever chunk of any brain researchers have attempted to map”, says Google.