In an extensive scientific endeavor supported by the National Institutes of Health (NIH), researchers have meticulously mapped the intricate connections between hundreds of thousands of neurons in the mouse brain. This project provides valuable insights into how visual information is processed by our brains—a vital step toward comprehending the reconstruction of visual images that define our daily experiences.
In the human brain, information processing is governed by the electric activity of 86 billion neurons forming trillions of connections. Understanding the brain's wiring and its electrical signaling could unlock secrets about cognitive and sensory functions, offering guidance on disorders or injuries.
During the study, scientists presented video clips to genetically engineered mice whose neurons emitted light when activated. The firing patterns were recorded in brain areas related to vision across a tiny tissue segment, measuring just a cubic millimeter but encompassing extensive complexity, including four kilometers of axons and over 524 million synapses.
Mapping these connections involved continuous 12-hour shifts for 12 days, cutting and imaging brain slices using electron microscopes. The reconstruction of these images, totaling nearly 28,000, was a major challenge and utilized deep learning algorithms for tracing and validating connections. The data amassed equals 1.6 petabytes, comparable to a continuous 22-year stream of HD video.
These discoveries coincide with a growing number of neuron maps shedding light on brain mysteries. Recent developments include the NIH BRAIN Initiative's complete cell atlas of the mouse brain, and the detailed mapping of the fruit fly brain.
Project funding stemmed from the Intelligence Advanced Research Projects Activity's Machine Intelligence from Cortical Networks Program and the NIH BRAIN Initiative. Results spanning 10 papers were published in the Nature journals, marking seven years of collaborative effort by over 150 scientists worldwide.
The mapped mouse connectome is available for online visualization through the MICrONS Explorer resource. For further comments, John Ngai, Ph.D., director of The NIH BRAIN Initiative, is accessible.
The NIH BRAIN Initiative facilitates cross-disciplinary discoveries to transform brain science, aiming to enhance treatments and understanding of brain disorders. It relies on partnerships aligning with its comprehensive research objectives.
The National Institute of Neurological Disorders and Stroke (NINDS) leads national research on the brain and nervous system, aiming to reduce neurological disease burdens. Representing 27 NIH institutes, NIH is part of the U.S. Department of Health and Human Services, supervising extensive medical research efforts.
