Mapping the brain - a new approach
9 May 2011 by Evoluted New Media
The brain is a highly intricate network of neurons connected to thousands of other neurons and researchers at University College London have developed a method to untangle the complexity.
The brain is a highly intricate network of neurons connected to thousands of other neurons and researchers at University College London have developed a method to untangle the complexity.
Connectomics aims to map the brain’s connections – or synapses – to understand how information flows through the brain and what goes wrong in neurodegenerative diseases.
“How do we figure out how the brain’s neural circuitry works?” said Dr Tom Mrsic-Flogel, a Wellcome Trust Research Carer Development Fellow at UCL. “We first need to understand the function of each neuron and find out to which other brain cells it connects.”
“If we can find a way of mapping connections between nerve cells of certain functions, we will then be in a position to begin developing a computer model to explain how the complex dynamics of neural networks generate thoughts, sensations and movements.”
Using high-resolution imaging, Mrsic-Flogel was able to detect which neurons in the visual cortex of the mouse brain responded to certain stimuli. Taking a slice of the same tissue, the researchers applied a small current to a subset of neurons to see which other neurons responded. By repeating this technique several times, researchers were able to trace the function and connectivity of hundreds of nerve cells in the visual cortex.
The study has resolved whether local connections between neurons are random or ordered – neurons that respond to similar stimuli tend to connect to each other much more than those that prefer different orientations.
Researchers now hope to begin generating a wiring diagram of a brain area with a particular behavioural function – such as the visual cortex – and hope to reveal the functional circuit wiring of regions that underpin touch, hearing and movements.
“We are beginning to untangle the complexity of the brain,” said Mrsic-Flogel. “Once we understand the function and connectivity of nerve cells spanning different payers of the brain, we can begin to develop a computer simulation of how this remarkable organ works.”
He said it will take many years of concerted efforts amongst scientist and massive computer processing power before this aim can be realised.
