One of the last frontiers of the unexplored left on earth, the living human brain, is yielding up its secrets to a new tool developed in Britain.
The revolutionary development allows researchers to see with extraordinary clarity the networks of nerve fibres - "white matter" - which link the different, thinking units of the brain, or "grey matter."
Known as Vivid, for virtual in-vivo interactive dissection, the system harmlessly picks out patterns of nerve connections inside the brains of living people. The pathways are uncannily similar to those which previously could only be pictured by a draughtsman, laboriously sketching the bisected brains of the dead.
Vivid is already being used to voyage into the brains of 30 British sufferers of schizophrenia, in a bid to solve one of the greatest of medicine's mental mysteries: are schizophrenics wired up differently to the rest of the population, and if so, how?
Developed by a team at the Institute of Psychology, part of King's College London, Vivid has the potential to enable breakthroughs in the understanding of a range of other conditions, including alchoholism, motor neurone disease, dyslexia, Alzheimer's, and multiple sclerosis.
It will enable scientists to see how the brain's wiring changes as children grow up, and when we get old. Ultimately, it will help doctors diagnose illnesses of the brain.
"When I show this to some psychiatrists, they go a bit crazy, because this is exactly what they want to look at," said Derek Jones, 29, the physicist who led development of Vivid.
One of the virtues of Vivid is that it requires no new hardware, just a reprogramming of the existing MRI (magnetic resonance imager) scanners which have long been in use in hospitals and labs around the country. Vivid is a refinement of a technique originally proposed by US scientists in the early 1990s.Traditional MRI scanners work by measuring the resonance of water molecules in the body when they are bombarded by radio waves in a magnetic field.
Vivid advances on that by tracking the random oscillation of water molecules in different directions. Because the molecules can move more easily along a bundle of fibres than around it, it is possible for a complex work of maths and computer programming to build up a three-dimensional picture.
Dr Jones has been invited to institutes in the US and Australia to install Vivid.
The King's College team is not the only group working on this type of imaging. But it is the only one whose system is capable of picking out individual bundles of nerve fibres at the resolution necessary to trace their exact route from one part of the brain to another. Conventional MRI scans were able to see inside the brain, but could not get a clear picture of the white matter.
Previously, a researcher looking at the brain's wiring was like an electrician who could only find faults by cut ting through a bunch of unidentified cables and studying the exposed faces of copper. Now, it is possible to follow a single "cable" from one "appliance" to another.
Scientists have theorized that schizophrenic behaviour may be the result of problems in the connections between two parts of the brain. Now it will be possible to use Vivid, and MRI, to find out the truth.
Backed with funding from the Wellcome Trust, Dr Jones and his colleagues have been scanning the brains of 60 people - 30 with schizophrenia, 30 without. Early results are said to be encouraging, although the team is saying nothing more until their work is published.
Ultimately, the group hopes psychiatrists will be able to use the system for routine diagnosis. And there is hope that new, more powerful MRI machines, such as one soon to be installed at King's, will be able to focus in on the brain's circuitry in even more detail.
