New technique helps mapping the brain
Mon, 11 Apr 2011 09:17:09 GMT
Scientists have moved closer to make a computer model of the brain by developing a technique to map both the connections and functions of nerve cells for the first time.
Researchers from Britain's University College London (UCL) have built a technique in mice, which enabled them to combine information about the function of neurons with details of their connections altogether.
The study is part of an emerging area of neuroscience research known as 'connectomics'. The new field, like genomics that maps our genetic make-up, aims to map the brain's connections known as 'synapses'.
According to estimates, there are about one hundred billion nerve cells ('neurons') in the brain, each connected to thousands of other nerve cells, making an estimated 150 trillion synapses.
Mapping these connections would show how information flows through the circuits of the brain. The data may help scientists understand how perceptions, sensations and thoughts are generated in the brain and how these functions go wrong in diseases such as Alzheimer's disease, schizophrenia and strokes.
In the new study published in the journal Nature, the researchers looked into the visual cortex of the mouse brain and determined which neurons responded to certain stimuli.
Then they applied small currents to a group of neurons to observe the responses of other neurons and figure out if they were connected by synapses.
By repeating this technique many times, the scientists were able to trace the function and connectivity of hundreds of nerve cells in visual cortex.
The research team is planning to study the structure and function of other regions in the brain to make a complete map of the most complicated and important part of the body almost controlling the whole other organs.
The new study has also resolved the debate about whether local connections between neurons are random or are based on their close function and task.
By the new study, researchers showed that neurons, which responded very, similarly to visual stimuli, tend to connect to each other much more than those that prefer different tasks.
"We are beginning to untangle the complexity of the brain," said Dr. Tom Mrsic-Flogel, lead researcher. "Once we understand the function and connectivity of nerve cells spanning different layers of the brain, we can begin to develop a computer simulation of how this remarkable organ works. But it will take many years of concerted efforts amongst scientists and massive computer processing power before it can be realized."
The technique may also help scientists and doctors to get a better and more detailed understanding about several brain functions as well as the nature of disease in the neural system that brings significant steps in the diagnosis and treatment of these illnesses.