This complex web of fibres is in fact a digital model of a small chunk of rat brain — containing 31,000 neurons, 37 million synapses and the ability to fire just like a living chunk of grey matter.
It’s small, sure — in fact, the structure is equivalent to a piece of real brain that would measure just one third of a millimetre cubed — but it’s the biggest achievement so far of the Blue Brain project, which has been running for 10 years. The long-term goal of the project is to create an accurate digital model of the entire human brain, which could be used for all kinds of experiments.
The chunk of digital rat brain is built up from models of 207 different types of brain cells, all created following intensive study of a small brain region by 82 different people. The team pieced together 1,000 neurons from scratch, and then used algorithms to assemble that basic building block into a more complex 31,000-neuron structure. The research is published in Cell.
The team is able to digitally stimulate the chunk of brain and then watch how signals propagate through it. So far their experiments have shown it behaves much like the real thing, with the same types of firing and delays as occur in real, live rat.
There’ still some way to go, of course, before a third-of-a-millimetre cube scales up to the size of a human brain — but it’s a step in the right direction.
Image by Makram et al./Cell 2015Makram et al./Cell 2015