NEW DELHI: Using a Japanese super-computer, a team of scientists have carried out the largest ever imitation of the way a brain's cells connect with each other. This will pave the way for a better understanding of the extremely complex human brain, they say. Researchers from the RIKEN, a Japanese research body, the Okinawa Institute of Science & Technology (OIST) in Japan and the Forschungszentrum Julich, a research institute in Germany, used the K-computer in Julich to carry out the neuronal network simulation. The brain consists of some 200 billion nerve cells, also called neurons. These are linked to each other by trillions of connections called synapses. Small electrical impulses are fired across the neurons through synapses, each of which contains an estimated 1000 switches for routing the message. The total network runs into hundreds of trillions of pathways. Just the topmost layer of the brain, the cerebral cortex has an estimated 125 trillion synapses, according to research by Stephen Smith, a professor at Stanford University. The latest simulation managed to create a virtual or electronic neuronal network of 1.73 billion nerve cells connected by 10.4 trillion synapses. For this feat, it used a open-source software called NEST and 82,944 processors of the K computer. The process took 40 minutes, to complete the simulation of 1 second of neuronal network activity in real, biological, time.