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Degrees of consciousness captured in real-tim -

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Degrees of consciousness captured in real-time for the first time

Lexi Metherell reported this story on Saturday, June 11, 2011 08:22:00

EMILY BOURKE: The state of unconsciousness is largely a mystery, but for the first time, it can now
be viewed in 3D.

Researchers in Manchester in the UK have constructed a movie of the brain changing as an
anaesthetic takes effect.

They say it adds to evidence that consciousness isn't an all-or-nothing state.

Lexi Metherell has this report.

LEXI METHERELL: No one really knows what happens when an anaesthetic is administered, and that's
partly because brain imaging technology hasn't been able to keep up with the brain.

BRIAN POLLARD: The brain is a high-speed electrical organ and technology wasn't at a point where
machines which were fast enough could be built.

LEXI METHERELL: Until now. A team at the University of Manchester has developed high-speed imaging
equipment which captures real-time images of the brain.

It's produced what's believed to be the first movie of the brain moving from consciousness to
unconsciousness and, in 3D.

The university's Professor of Anaesthesia is Brian Pollard. He and his team have been able to watch
the changes in the brain after administering a dose of an anaesthetic to a patient.

BRIAN POLLARD: It seems to start within the brain stem and the mid-brain and spread throughout the
rest of the brain and various areas I'll say light up or there is a change in conductivity and the
other thing that struck us is that some of these areas appear to be communicating with each other -
there seems to be paths of communication opening and closing between these areas.

LEXI METHERELL: The images seem to suggest that losing consciousness involves a change in
electrical activity deep in the brain, which changes the activity of certain nerve cells and
interrupts communication between different parts of the brain.

And that supports a theory put forward by Professor of Synaptic Pharmacology at Oxford University,
Susan Greenfield - that consciousness is not an all-or-nothing state.

Her theory is that there are degrees of consciousness, which match up with the formation of groups
of brain cells also known as neural assemblies.

SUSAN GREENFIELD: My frustration has been that these so-called assemblies, these coalitions of
brain cells, because they are corralled up and then disbanded in less than a second, that this
would be too fast for the much slower time scale of conventional brain imaging.

And that's why this is for me a great advance and very exciting for me because it validates my

LEXI METHERELL: Professor Greenfield says it's not surprising that the images suggest that
unconsciousness starts from the brain stem - an area of the brain where there are fountains of
chemicals like serotonin and dopamine which spread throughout the brain.

SUSAN GREENFIELD: These chemicals can act as modulators, that's to say they can aid and abet and
facilitate the formation of assemblers by modulating, by making the cells more easy to corral up.

So it makes every sense to me that things would start in the brain stem where, I say it's a very
primitive part of the brain in evolutionary terms, but also it's a kind of centre that energises
the rest of the brain, that allows it to be more sensitive to stimulation or otherwise, that
modulates the activity of different groups of brain cells in many different brain areas.

LEXI METHERELL: She says the high-speed imaging equipment is great advance. Professor Brian Pollard

BRIAN POLLARD: Now we are beginning to be able it seems to put together a changing function within
the brain during the onset of anaesthesia, and that is another piece of the jigsaw, another step
forward towards an understanding anaesthesia and possibly then going backwards to understanding

LEXI METHERELL: The findings of the research are being presented today at the European
Anaesthesiology Congress in Amsterdam.

EMILY BOURKE: Lexi Metherell with that report. And pictures of those images recorded by the
scientists will be on the AM website shortly.