In a huge first for science, researchers have cracked the code of a rat’s brain — sort of.
In a recent test, they were able to successfully simulate a portion of the brain, creating a computer model that lined up fairly closely with real world experiments involving rats, according to a UPI report.
It was all part of the Blue Brain Project, which itself is a subset of the larger Human Brain Project — mankind’s attempt to build a computer model of the human brain, something that many argue is impossible. This most recent test may throw some cold water on the skeptics, although scientists admit we’re still a very long way from mapping out the human brain. They published their findings in the journal Cell.
It’s definitely a huge step forward for science and a major milestone that could lead to future breakthroughs, as well as indicate this crazy project may actually have a chance of working.
Basically, the researchers made a “computerized neocortex.” This involved mapping out 30,000 neurons and 40 million synapses, and uploading all the rules and definitions for how they interact with each other. Scientists were able to take this map and create a model of the neocortex, from which they could run simulations. It was all thanks to this algorithm, and past data from previous rat studies.
The computer model created results that correlated very strongly with rat brain experiments that have been conducted in real world tests, indicating that this model works.
They didn’t upload all the data, just the amount necessary to demonstrate a model could be built. They’ll really have their work cut out for them tackling the human brain, which has 85 billion neurons.
Not everyone is buying in the Human Brain Project, but this latest test certainly makes it much easier, and gives reason why it should continue to be funded, even if a human model is a long way down the road.
The scientists talked more about the project in a press release, explaining the purpose of the test and what they hope to accomplish down the line.
Why did they perform 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.'”
What simulations did they run? “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.”
What’s next on the docket? “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.”