Thanks to a mouse viewing segments from 'The Matrix,' Scientists have developed the most extensive functional map of a brain so far – an illustration depicting how 84,000 neurons connect as they transmit signals.
With just a tiny portion of the mouse’s brain, roughly the size of a poppy seed, the scientists were able to pinpoint these specific neurons and follow their communication pathways across an unexpected network involving approximately 500 million synaptic connections.
The extensive dataset released on Wednesday in the journalNature represents progress towards solving the puzzle of understanding how our brains work.
The data, assembled in a 3D reconstruction colored to delineate different brain circuitry, is open to scientists worldwide for additional research – and for the simply curious to take a peek.
"Forrest Collman from the Allen Institute for Brain Science in the U.S., one of the key researchers involved in this project, remarked, 'It certainly evokes a feeling of wonder, much like viewing images of distant galaxies,' " he stated.
You start to understand your own intricacy. We're examining just a small section of a mouse's brain, yet the elegance and complexity evident in these individual neurons and their hundreds of millions of interconnections are astounding.
How we think, feel, see, talk, and move are due to neurons, or nerve cells, in the brain – how they’re activated and send messages to each other.
Scientists have been aware for a long time that these signals travel through neurons via structures known as axons and dendrites, utilizing synapses to leap to the subsequent neuron.
However, lesser-known details exist regarding the neuron networks responsible for specific functions and how disturbances in their connections might contribute to various roles in neurological issues. Alzheimer's , such as autism or other conditions.
For the new initiative, over 150 scientists from around the world teamed up to chart neuronal pathways within a section of the mouse brain associated with sight; these paths were likened by Collman to strands of spaghetti thrown into disarray.
How researchers charted the human brain
The first step: show a mouse video snippets of sci-fi movies, sports, animation, and nature.
A team at Baylor College of Medicine in the US did just that, using a mouse engineered with a gene that makes its neurons glow when they’re active.
The scientists employed a laser-driven microscope to capture how specific cells within the creature's visual cortex became active as they interpreted the rapidly changing images.
Subsequently, researchers from the Allen Institute examined that minuscule section of brain matter by employing a specialized device to slice it into over 25,000 sections and capturing almost 100 million high-resolution photographs with electron microscopes. Following this, they meticulously reconstructed these pieces into a three-dimensional model.
Lastly, researchers at Princeton University in the U.S. employed artificial intelligence (AI) to map out all those connections and "assign a distinct color to each wire so they can be identified separately," according to Collman.
They projected that if extended, the tiny wires would stretch over 5 kilometers.
Implications for human health
Could this kind of mapping assist researchers in ultimately discovering cures for neurological disorders?
The researchers refer to this as a fundamental milestone, similar to how the Human Genome Project, which offered the initial genetic map, ultimately paved the way for therapies based on genes.
One of the upcoming objectives is to map an entire mouse brain.
"The innovations from this initiative will provide us with our initial opportunity to genuinely pinpoint an unusual pattern of connectivity that leads to a disorder," stated Sebastian Seung, a Princeton-based neuroscientist and computer scientist who is one of the key figures in the project.
"The effort represents a significant advancement and provides an indispensable community asset for forthcoming revelations," noted Harvard neuroscientists Mariela Petkova and Gregor Schuhknecht, who were not part of the initiative.
The extensive and collectively accessible data "will aid in deciphering the intricate neural networks that underlie cognitive processes and behaviors," they mentioned additionally.