The best method to learn how something works, is to disassemble it and try it again. Researchers claim that they have successfully done this with a piece of the juvenile rat brain. In the journal Cell, the scientists explain how they created the initial draft. This reconstruction includes more than 31,000 neuron layers, fifty-five cells and 207 distinct neuron subtypes.
Researchers are attempting to identify all types of brain neurons, measure their electrical firing characteristics, and map the interconnected circuits. This is what scientists call ‘heroic effort’.
They are beginning to provide insight into the logic and building blocks that make up the brain’s wiring. It is not easy to see the brain’s features and activities in detail.
Part of the BlueBrain Project: Rat Brain Prof.
Henry Markram is currently working at EPFL (Ecole polytechnique federale de Lausanne), in Switzerland. He and his team took an engineering approach when addressing this question. Digital reconstruction of a portion of the young rat’s neocortex has been done.
The brain’s neocortex, which is part of the cerebral cortex that deals with sight and hearing in mammals, can be digitally reconstructed. This is the oldest part of cortex. Blue Brain Project is an effort to reverse engineer human brains and rebuild them at the cellular level in a computer simulation. Researchers created a virtual slice of the human brain that represented the various types of neurons in the region. They also identified the main features responsible for their firing.
The researchers also constructed a virtual brain slice that represented the connectivity of neurons, with almost 40 millions synapses as well as 2 ,000 connections among each type of brain cell. Professor Henry Markram. Professor Henry Markram stated that the reconstruction involved a lot of experimentation.
This allows one to predict the number, location and amount of ion flows through each million synapses. It was amazing to see that they could produce wider patterns of circuit-level activity by adjusting one parameter, the calcium ion level. This is something that cannot be predicted from individual neuron characteristics.
In their simulations, they were able to trigger slow, synchronous waves in neuronal activity that have been observed in the brain while it sleeps. These results suggest that neural circuits could switch between’states’, which may be necessary to underlie certain behaviors.
Professor Markram stated that a computer processor can be reconfigured to concentrate on specific tasks. These experiments indicate the existence of multiple states.
This raises questions such as “what happens if you get stuck in the wrong place?” The team believes that the findings could help to explain why the fight or flight response via the adrenocorticotropic hormonal triggers aggression and tunnel vision. Blue Brain Project researchers say that they intend to continue exploring state-dependent computation theory and improving their model. You can access their results here.