An international team of scientists created the first detailed map of wiring neuronal of an adult brainmarking a historic advance in neuroscience. This achievement, carried out in the brain of a fruit fly, could open new avenues for understanding how the brain works human health and its deterioration in diseases such as Alzheimer’s disease and other dementias.
Thus, with the first complete diagram of the neuronal wiring of an adult brain, with the identification of each of its neurons and the 50 million the connections that connect themin the brain of a fruit fly, this milestone was achieved thanks to an international group of scientists from the FlyWire Consortium, which includes experts from MRC and University of Cambridge Molecular Biology Laboratory (United Kingdom), in collaboration with researchers from the universities of Princeton and Vermont (USA). The results were published in two articles in the journal Nature.
Dr. Gregory Jefferisof the Molecular Biology Laboratory of the MRC and the University of Cambridgewho was one of the co-leaders of the research, comments: “If we want to understand how the brain works, we need a mechanistic understanding of how all the neurons come together and allow you to think. “For most brains, we have no idea how these networks work.”
“Flies can do all kinds of things complicated things, like walking, flying, finding your way, and males sing to females. The brain’s wiring diagrams are a first step to understanding everything that interests us: how we control our movements, answer the phone or recognize a friend,” he warns.
The map, which covers 139,255 neurons in the brain of an adult fly, is the first to record all the connections in the entire brain of an animal capable of walking and seeing. Previous studies have produced complete maps of much smaller brains, such as that of the fruit fly larva, which has 30.016 neurons, or the nematode worm, which has 302 neurons.
Researchers say mapping the fly’s complete brain is a key first step toward achieving larger brains. From the fruit fly It is a common tool in researchtheir brain map can be used to advance our understanding of how neural circuits work.
For his part, Dr Mala Murthyof Princeton University, one of the co-leads of the research, adds: “We have made the entire database available to all researchers, free and open. We hope it is transformer for neuroscientists who try to better understand how a healthy brain functions. “In the future, we hope it will be possible to compare what happens when things go wrong in our brains, for example in mental health disorders.”
The scientists found that there were substantial similarities between the wiring of this board and previous smaller-scale work that had been done. mapped parts of the fly brain. This led researchers to conclude that there are many similarities in the wiring between individual brains and that each brain is not a single structure like a snowflake.
By comparing your brain diagram with previous diagrams of small areas of the brain,The researchers also found that about 0.5% neurons exhibit developmental variations that could result in poor connection between neurons. The researchers say this will be an important area for future research to understand whether these changes are linked to individuality or brain disorders.
The brain of an entire fly is less than a millimeter wide. The researchers started with a female brain cut into seven thousand slices, each just 40 nanometers thick, which were previously scanned by high-resolution electron microscopy in the laboratory of the project co-director, David Bockthen to the Janelia Research Campus in the United States.
Analyze over 100 terabytes of image data (equivalent to the storage of 100 typical laptops) to extract shapes from approximately 140,000 neurons and 50 million connections among them, it is too difficult for humans to do manually. The researchers therefore relied on artificial intelligence developed at Princeton University to identify and map neurons and their connections between them.
However, AI still makes many errors on data sets of this size. The FlyWire Consortium, comprised of teams from more than 76 laboratories and 287 researchers from around the world, as well as volunteers from the general public, spent approximately 33 person-years carefully reviewing all the data.
Dr. Sebastian Seung of Princeton University, one of the leaders of the research, reveals: “Whole-brain mapping has been made possible by advances in AI computing; It would not have been possible to manually reconstruct the entire wiring diagram. This is an example of how AI can advance neuroscience. “The fly brain is an important step on our path toward reconstructing a wiring diagram of the entire mouse brain.”
