Neuroscientists who have been delving into the brain’s architecture say the nerves in the human brain comprise a 3D grid of criss-crossing fibres. Their findings have been recently published in Science.
The researchers behind the Human Connectome Project hail from Massachusetts General Hospital in Boston and UCLA.
Using advanced neuroimaging methods, they are constructing a map of the complete structural and functional neural connections in the human brain. Their aim is to navigate the brain in 3D to compare essential circuits and zoom into specific regions of the brain to explore cell make-up.
According to the researchers, it’s the first large-scale attempt to collect and share data of a scope to begin the process of addressing deeply fundamental questions about human connectional anatomy and variation.
In an interview with Nature, Van Wedeen, a neuroscientist at Massachusetts General Hospital, said the grid creates a scaffold to guide brain development and support more complex and variable brain structures.
"The grid structure, by dint of its simplicity and symmetry under deformation, allows for continuous re-wiring," he told Nature.
He also indicated that the scientists were surprised to find out that the nerve fibre bundles form a regular network, rather than a jumbled mass.
So how are they mapping the brain in 3D?
The researchers involved in the Human Connectome Project, which incidentally is a US government-funded project, have been carrying out trials with human beings using a diffusion-imaging scanner, called the Connectome Scanner, which was built by Siemens. The scanner is based at Massachusetts General Hospital.
In analysing the brain’s architecture, the scientists are now working one group of fibres at a time to compute the distribution of orientations for this group.
"This approach produces beautiful local 2D co-ordinate patches throughout most or all of the brain. Our present effort is to standardise this and devise methodology to glue together local co-ordinate patches into larger 3D and regional co-ordinates, with the ultimate aim to create a standard, unified fibre-based co-ordinate system for the brain," said the researchers.