An international research group of which theUniversity of Montreal (The University of Montreal is one of the four educational institutions …) achieved a breakthrough by accurately simulating the synaptic changes in the neocortex that are believed to be essential for thelearning (Learning is the acquisition of know-how, i.e. the process …)thus paving the way for a better understanding of how the brain (The brain is the main organ of the central nervous system of animals. The brain processes …).
The study of scientists – which is based on a model with source code (The source code (or sources or even the source) is a set of instructions written in a …) open – was posted on 1uh June to Nature Communications.
A world of new directions
“A world of new directions of investigation opens up. scientific (A scientist is a person who devotes himself to the study of one or more sciences and who …) about how we learn, ”said Eilif Muller, assistant professor in the Department of neuroscience (Neuroscience corresponds to the set of all biological disciplines and …) by UdeM, researcher (A researcher (female researcher) refers to a person whose job is to do research …) at IVADO – onInstitute (An institution is a permanent organization created for a specific purpose. It is …) evaluation of data (In information technology (IT), data is an elementary description, often …) – and holder of an ICRA-Canada chair in artificial intelligence (Artificial intelligence or cognitive computing is “finding means …) (IA), who co-directed the study at the Blue Brain Project at the École polytechnique fédérale de Lausanne (EPFL), Switzerland.
Eilif Muller moved to Montreal (Montreal is both an administrative region and a metropolis of Quebec. So big …) in 2019 and continues his research in the laboratory Architectures (Architectures is a documentary series proposed by Frédéric Campain and Richard Copans, …) of Biological Learning, which he founded at the Center for Research (Scientific research primarily refers to all actions undertaken with a view to …) of the CHU Sainte-Justine in association with UdeM and Mila, the Quebec Institute of Artificial Intelligence.
“Neurons are shaped like a tree (A tree is a terrestrial plant capable of developing on its own in height, in …) and the synapses are the leaves on the branches, explained Professor Muller, co-lead author of the study. Previous approaches to modeling plasticity ignored this tree structure, but we now have the computational tools to test the idea that synaptic interactions on branches play a vital role in driving learning. inhabit (In vivo (in Latin: “inside the living”) is a Latin expression …). “
“This has important implications for understanding the mechanisms of neurodevelopmental disorders such asautism (The term autism today tends to designate a disorder that affects the person in three …) and the schizophrenia (The term schizophrenia generically includes a set …)but also for development point (graphics) powerful new approaches to AI inspired by neuroscience. ”
Employees in five countries
Eilif Muller collaborated with a group of scientists from the EPFL’s Blue Brain Project,University of Paris (The University of Paris was one of the largest and most …)of the’Hebrew University of Jerusalem (The Hebrew University of Jerusalem (in Hebrew …)Instituto Cajal (Spain) and Harvard Medical School to develop a model of synaptic plasticity in the neocortex based on dynamic (The word dynamic is often used to designate or qualify what refers to movement. It …) from soccer (Calcium is a chemical element, symbol Ca and atomic number 20.) postsynaptic under data constraint.
How does it work? Simpler than you might think.
The brain is made up of billions of neurons that communicate with each other forming (In pitch, fundamental frequency changes are perceived as variations of …) trillions of synapses. These connection points between neurons are complex molecular machines that constantly change under the influence of external stimuli and internal dynamics, a process commonly referred to as synaptic plasticity.
In the neocortex, a key area associated with learning high-level cognitive functions in mammals, pyramidal cells account for 80-90% of neurons and are known to play an important role in learning. Despite their importance, the long-term dynamics of their synaptic changes have only been experimentally characterized among some of their types and have been shown to be diverse.
Therefore, understanding of the complex neural circuits formed, particularly through the stereotyped cortical layers, which determine how the various regions of the neocortex interact, is limited. The innovation of Eilif Muller and her colleagues was the use of modeling informatics (IT – contraction of information and automatics – it is the domain …) to gain a more complete view of the dynamics of synaptic plasticity that govern learning in these neocortical circuits.
By comparing their results with the available experimental data, they showed in their study that their model of synaptic plasticity can explain the various dynamics of plasticity of the various pyramidal cells that make up the neocortical microcircuit. They achieved this by resorting to a single together (In set theory, a set intuitively designates a collection …) parameters of the model, indicating that the rules of neocortical plasticity could be shared by all types of pyramidal cells and thus be predictable.
Most of these plasticity experiments were performed on rodent brain slices in vitro (In vitro (Latin: “in the glass”) indicates a test tube, or other …), where the calcium dynamics that regulate synaptic transmission and plasticity are significantly altered compared to learning in the intact brain in vivo. Importantly, the study predicts plasticity dynamics that are qualitatively different from the reference experiments performed in vitro.
If this were confirmed by future experiments, the implications for our understanding of plasticity and learning in the brain would be important, believe Eilif Muller and her team.
“The interesting thing about this study is that it is further confirmation for scientists that we can overcome gaps in experimental knowledge by using a modeling approach when studying the brain,” said Henry Markram, EPFL neuroscientist, founder and director. of the Blue Brain Project.
It is open science
“Furthermore, the model is open-source, available on the Zenedo platform,” he added. Here we have shared hundreds of plastic connections of pyramidal cells of different types. Not only is it the most widely validated model of plasticity in this one day (The day or day is the interval between sunrise and sunset; it is the …)but it also represents the most complete prediction of the differences between the plasticity observed in a petri dish and in an intact brain. “
Henry Markram concluded by saying that “this leap forward is made (Rendering is a computer process that calculates the 2D image (equivalent to a photograph) …) possible thanks to our team-based collaborative science approach. In addition, the community can go further and design their own versions by modifying or supplementing them. It is open science and it will accelerate progress. “
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