The human brain is so complex that scientific brains have difficulty understanding this. A neural tissue piece of the size of a sand grain can be packaged with hundreds of thousands of cells connected to miles by cabling. In 1979, the Nobel Prize -winning scientist Francis Crick concluded that anatomy and activity in a cubic millimeter brain will overcome our understanding forever.
“It doesn’t help to ask for the impossible,” Dr. Crick written.
Forty-six years later, a team of more than 100 scientists is less than one percent of the volume of complete by recording cellular activity and mapping the structure in the cubic millimeter of a mouse’s brain. While performing this success, they collected 1.6 Petabayt data, the equivalent of 22 years of uninterrupted high -definition video.
“This is a milestone, Dav said Davi Bock, a neuroscientist at the University of Vermont. studyIt was published in Nature magazine on Wednesday. Dr. Bock, for a new target, it is possible to draw a cubic millimeter brain body: Map the cabling of the entire brain of a mouse.
“It can be done completely and I think it’s worth doing,” he said.
More than 130 years Spanish neuroscientist Santiago Ramón Y Cajal saw the individual neurons for the first time under the microscope and removed their branched shapes. Subsequent generations scientists have solved most of the details of how a neuron sent a voltage increase in a long arm called axon. Each axon comes into contact with small branches or dendrites of neighboring neurons. Some neurons excite their neighbors to fiery voltage increases. Some quiet other neurons.
Human thought somehow emerges from this mixture of stimulation and inhibition. But how it was a tremendous mystery, because because scientists could only examine a few neurons at a time.
In recent years, technological advances have allowed scientists to start their minds completely. British researchers in 1986 published The circuit of a small worm of 302 neurons. In the following years, the researchers drew larger brains such as 140,000 neurons in a fly brain.
After all, Dr. CRICK’s impossible dream is possible? American Government started in 2016 An effort of 100 million dollars Scan a cubic millimeter mouse brain. The project, called machine intelligence from cortical networks or microns, was directed by scientists at the Allen Institute of Brain Sciences, Princeton University and Baylor Medical Faculty.
Researchers reset to a portion of the mouse brain that reconstructs the signal of the brain and the animal sees. In the first stage of the research, the team recorded the activity of neurons in that region because of the mouse videos of different landscapes.
The researchers then shredded the mouse brain and soaked the cubic millimeter with hardening chemicals. Then they shaved 28,000 slices from the tissue block and caught an image of each. Computers are trained to recognize the outlines of cells in each slice and connect slices to three -dimensional shapes. They all drew 523 million neural connections as well as 200,000 neurons and other types of brain cells.
For Nuno Da Costa, one of the leaders of the Allen Institute and one of the leaders of the project, it was a breathtaking to watch the cells shaping only on the computer screen. “These neurons are absolutely striking – it gives me pleasure,” he said.
To understand how this neuron network works. Da Costa and his colleagues mapped the event recorded when they looked at the mouse videos.
“Imagine that you have come to a party with 80,000 people and you might be aware of every conversation, but you don’t know who you talk to, Da Costa said. “And now imagine that you have a way to know who he is talking to, but you have no idea what they say. If you have two things, you can tell a better story about what happened at the party.”
The researchers who analyze the data have discovered the patterns that have notified the brain so far. For example, they identified different types of inhibitor neurons connected to some other types of neurons.
“When you start examining the brain, it looks desperate – there is too much connection and too much complexity, Mar Mariela Petkova, a biophysicist who is not involved in the Micron project in Harvard. “Finding the rules of wiring is a gain. The brain is much less messy than people think,” he said.
Most of Micron researchers are now one Larger project: Mapping the brain of an entire mouse. With a volume of 500 cubic millimeters, a brain will last decades or centuries for graphics with existing methods. Scientists will have to find additional tricks to finish the project within ten years.
Gregory Jeffeis, a neuroscientist who is not included in the Micron project at the University of Cambridge, said, “The hero to come here,” he said. “But we still have a mountain to climb.”
Forrest Collman is a member of the Micron Project at the Allen Institute. He and his colleagues recently discovered how to make thin sections microscopically from the entire mouse brain. “Some of these obstacles are starting to fall, Dr. Dr. said. Collman.
However, about a thousand times larger than a mouse, our brain offers a much larger challenge, he added. “The human brain seems to be out of what is now possible,” he said. “We’re not going there soon.”
However, a neuroscientist and a member of the Micron Project in Princeton, however, said that mouse brains and human brains are as similar as to collect clues that can help researchers find drugs to effectively treat psychological disorders without causing harmful side effects.
“Our methods of manipulating the nervous system are incredibly blunt instruments, Seung Seung said. “You put a medicine and goes everywhere,” he added. “But actually to reach and manipulate a cell type – this is sensitivity.”
Efforts to Mapply a Mouse Brain supported By financing a long -term national health institutes called brain initiative. However, the future of the effort is uncertain. Last year, the congress provided funds for brain initiative 40 percentAnd last month, President Trump signed a 20 percent more invoice support support.
Dr. Bock said that the brain mapping efforts like Micron have taken years because they require the invention of new technologies and software along the way.
“We need the consistency and predictability of science financing to achieve these long -term goals, B said Bock.
