US researchers James Frye, Rajagopal Ananthanarayanan and Dharmendra S. Modha ran a "cortical simulator" that was as big and as complex as half of a mouse brain on the BlueGene L supercomputer. In other smaller simulations the researchers say they have seen characteristics of thought patterns observed in real mouse brains. In these other tests the team saw the groups of neurons form spontaneously into groups. They also saw nerves in the simulated connections firing in a ways similar to the staggered, co-ordinated patterns seen in nature.
The three researchers laid out how they went about it in a very short research note entitled "Towards Real-Time, Mouse-Scale Cortical Simulations". Half a real mouse brain is thought to have about eight million neurons – each one of which can have up to 8,000 connections, with other nerve fibres. The team, from the IBM Almaden Research Lab and the University of Nevada, ran the simulation thanks to the supercomputer's 4096 processors, each one of which used 256MB of memory. Using this machine the researchers created half a virtual mouse brain that had 8,000 neurons that had up to 6,300 connections. The vast complexity of the simulation meant that it was only run for ten seconds, at a speed ten times slower than real life.
For future tests the team aims to speed up the simulation, make it more neurobiologically faithful, add structures seen in real mouse brains and make the responses of neurons and syna-pses more detailed.