Forrest Collman/Allen Institute
International team of researchers creates the most advanced 3D map of the mouse visual cortex.
Work under the guidance of the MICrONS project allowed us to create a high-resolution three-dimensional map of a part of the visual cerebral cortex of the mouse, enabling scientists to radically change their understanding of the work and functions of this organ. The total amount of data was 1.6 petabytes of information, covering the activity of more than 200 thousand cells. The map includes 4 km of branched axons and 500 million synaptic centers.
«MICrONS achievements is a watershed moment for neuroscience, comparable to the human genome project in its transformative potential», — says lead author David Markowitz.
The study involved neuroscientists from Princeton University, the Allen Institute, and Baylor College of Medicine. The scientists monitored the activity of neurons in the visual cortex of the brain mouse based on a series of videos.
After that, the Allen Institute specialists used electron microscopy to create an image of this brain region, previously divided into 25 thousand ultra-thin fragments, each thinner than a human hair. Artificial intelligence scientists at Princeton used advanced AI algorithms to track and reconstruct the neural and synaptic connections of the cellular architecture. This model was subsequently converted into a three-dimensional one.
«Inside this tiny speck is a whole architecture, like an exquisite forest. It has all sorts of rules of connections that we knew from different parts of neuroscience, and within the reconstruction itself, we can test old theories and hopefully find new things that no one has ever seen before», — explains Senior Research Scientist Clay Reid.
One of the key discoveries for scientists was a change in the way inhibitory neurons work. It was believed that these neurons exclusively inhibit brain activity. However, as it turned out, they work very selectively. Whole groups of these neurons work in concert to inhibit certain sets of excitatory cells, while others focus exclusively on one type of cell.
This complex mechanism of inhibition and counterinhibition reveals a previously unknown balance in the coordination of neurons in information processing. In addition to revealing the architecture of thinking, it the study may reveal new opportunities for diagnosing and treating brain-related disorders such as Alzheimer’s disease, autism, and schizophrenia.
Source: Interesting Engineering