An Advance in Brain Research That Was Once Considered Impossible

Scientists achieved “a milestone” by charting the activity and structure of 200,000 cells in a mouse brain and their 523 million connections.

The human brain is so complex that scientific brains have a hard time making sense of it. A piece of neural tissue the size of a grain of sand might be packed with hundreds of thousands of cells linked together by miles of wiring. In 1979, Francis Crick, the Nobel-prize-winning scientist, concluded that the anatomy and activity in just a cubic millimeter of brain matter would forever exceed our understanding.

“It is no use asking for the impossible,” Dr. Crick wrote.

Forty-six years later, a team of more than 100 scientists has achieved that impossible, by recording the cellular activity and mapping the structure in a cubic millimeter of a mouse’s brain — less than one percent of its full volume. In accomplishing this feat, they amassed 1.6 petabytes of data — the equivalent of 22 years of nonstop high-definition video. (...)

In 2016, the American government began a $100 million effort to scan a cubic millimeter of a mouse brain. The project — called Machine Intelligence from Cortical Networks, or MICrONS — was led by scientists at the Allen Institute for Brain Science, Princeton University and Baylor College of Medicine.

The researchers zeroed in on a portion of the mouse brain that receives signals from the eyes and reconstructs what the animal sees. In the first stage of the research, the team recorded the activity of neurons in that region as it showed a mouse videos of different landscapes.

The researchers then dissected the mouse brain and doused the cubic millimeter with hardening chemicals. Then they shaved off 28,000 slices from the block of tissue, capturing an image of each one. Computers were trained to recognize the outlines of cells in each slice and link the slices together into three-dimensional shapes. All told, the team charted 200,000 neurons and other types of brain cells, along with 523 million neural connections.

by Carl Zimmer, NY Times |  Read more:

Image: uncredited

[ed. So, naturally: Trump administration suspends dozens of research grants to Princeton (CNN).]