http://www.guardian.co.uk/Archive/Article/0,4273,4337782,00.html
Friday January 18, 2002
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.
James Meek, science correspondent
Guardian
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