Researchers were able to simulate a rat's brain in a recent test.
Researchers have successfully simulated a portion of a rat’s brain in a recent test.
The scientists, who are part of what is known as the Blue Brain Project, are working as part of the Human Brain Project in order to figure out how to build a computer model of a human brain — so, they’re starting with rats, according to a UPI report.
While this is in no way proof that the Human Brain Project will be successful, it’s an exciting step forward to scientists that could be big dividends down the line — and it’s certainly a major milestone for the project, and one that signals it could possibly work. The findings were published in the journal Cell.
The researchers created a computerized neocortex that includes 30,000 neurons connected by 40 million synapses. It was only partially uploaded — uploading everything would have been a massive project. The algorithm they built would instead be focused on identifying rules and definitions that govern neurons and synapses, and how they interact with each other.
Using this information, scientists were able to build a map of the neocortex, and from there were able to create a partial brain model. This was entirely due to the algorithm that scientists had created — much of which was based on previous data from rat brain studies.
Once they created the model, scientists moved on to simulating it. The results were exciting: they seemed to correlate with rat brain experiments in the real world, suggesting that the researchers were on the right track.
Still, while this is certainly a massive success, researchers have a long way to go before they say they have conquered the human brain. They’ll need to simulate a whopping 85 billion neurons in order to accomplish that.
There are still people who doubt the feasibility of the Human Brain Project, but this at least is a step in the right direction, and a sign that it might be possible. But it will be a long way down the road.
On why they performed the project: “The aim of the study was to create a digital approximation of the tissue. The big test is how the circuit behaves when the interactions between all the neurons are simulated on a supercomputer. Of course, making this happen has been an enormous challenge for the project’s engineers, as well as for the scientists. As reported by Felix Schürmann, a senior author who leads the team that builds the sofware to run on supercomputers: ‘Building the digital reconstructions, running the simulations and analyzing the results required a supercomputing infrastructure and a large ecosystem of software. It was only with this kind of infrastructure that we could solve the billions of equations needed to simulate each 25 microsecond time-step in the simulation.'”
On the simulations they ran: “The researchers ran simulations on the virtual tissue that mimicked previous biological experiments on the brain. Even though, the digital reconstruction was not designed to reproduce any specific circuit phenomenon, a variety of experimental findings emerged. One such simulation examined how different types of neuron respond when the fibers coming into the neocortex is stimulated by incoming fibers – analagous to touching the skin. The researchers found that the responses of the different types of neurons in the digital reconstruction were very similar to those that had been previously observed in the laboratory. They then searched the reconstruction for exquisitely timed sequences of activity (“triplets”) in groups of three neurons, that other researchers had previously observed in the brain. They found that the reconstruction did indeed express the triplets and also made a new discovery: the triplets only occur when the circuit is in a very special state of activity. They further tested whether the digital reconstruction could reproduce the recent discovery that some neurons in the brain are closely synchronized with neighboring neurons (dubbed, “chorists”), while others operate independently from the group (“soloists”). The researchers found the chorists and soloists, and were also able to pin-point the types of neurons involved and propose cellular and synaptic mechanisms for these behaviors.”
On what’s next: “The reconstruction is a first draft, it is not complete and it is not yet a perfect digital replica of the biological tissue”, says Henry Markram. In fact, the current version explicitly leaves out many important aspects of the brain, such as glia, blood vessels, gap-junctions, plasticity, and neuromodulation. According to Sean Hill, a senior author: “The job of reconstructing and simulating the brain is a large-scale collaborative one, and the work has only just begun. The Human Brain Project represents the kind of collaboration that is required.”