Blue brain power

The human brain has 100 billion neurons, nerve cells that enable us to adapt quickly to an immense array of stimuli. We use them to understand and respond to bright sunlight, a honking horn, the smell of chicken frying and anything else our sensors detect.

To better understand some of those responses, researchers in Lausanne, Switzerland, recently launched an ambitious project called Blue Brain, which uses IBM's eServer Blue Gene, a supercomputer capable of processing 22.8 trillion floating point operations per second (TFLOPS). Blue Brain is modeling the behavior of 10,000 highly complex neurons in rats' neocortical columns (NCC), which are very similar to the NCCs in a human brain. The NCCs run throughout the brain's gray matter and perform advanced computing. They are 0.5mm in diameter and 2mm to 5mm in height and are arranged like the cells of a honeycomb.

The first objective of Blue Brain is to build an accurate software replica, or template, of an NCC within two to three years, says Henry Markram, the principle researcher on Blue Brain and a professor at Ecole Polytechnique Federale de Lausanne (EPFL). That first template will be modified for NCCs found in different brain regions and species, and then all the NCCs will be replicated to build a model of the neocortices of different species, he says.

Such models will shed light on how memories are stored and retrieved, Markram says. "This could reveal many exciting aspects of the [brain] circuits, such as the form of memories, memory capacity and how memories are lost."

The modeling can help find vulnerabilities in the neocortex, which is useful because that's where brain disorders often originate. "We may also be able to work out the best way to compensate and repair circuit errors," Markram says. "The model could be used to develop and test treatment strategies for neurological and psychiatric diseases," such as autism, schizophrenia and depression, he adds.

Having an accurate computer-based model of the brain would mean that some major brain experiments could be done in silicon rather than in a "wet" lab. A simulation that might take seconds on the supercomputer could replace a full day's worth of lab research, Markram estimates. Ultimately, simulated results of brain activity could be matched with recorded brain activity in a person with a disease in order to "reverse-engineer" the circuit changes in diseases, he says.