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> > I thought that the notion that one side of  the brain is dominant is
> > "old hat" and is well known.


this is new too:


Study provides new insights into brain organisationStudy provides new insights 
into brain organisation

Date released 1 August 2006 

Scientists have provided new insights into how the brain is organised - 
knowledge which could eventually inform diagnosis of and treatments for 
conditions like Alzheimer's Disease and autism. 
A study by Newcastle University and the International University Bremen, 
Germany, debunked a prevailing theory that the nervous system should have 
mainly very short nerve fibre connections between nerve cells, or neurons, to 
function at its most effective. 
Instead the study, which carried out a sophisticated computer analysis of 
public databases containing detailed information of worldwide anatomical 
studies on primate and worm brains, found that long nerve fibre connections 
were just as vital to overall brain function as short ones. 
Much of what we know about the human brain derives from neuroscience research 
on primates, which are used because they have have experienced similar 
evolutionary stages to humans. 
Brain scans of Alzheimer's patients and people with autism have shown that 
they are lacking certain long-distance neural interactions, although experts 
have yet to discover their specific purpose. 
The new study, published in the academic journal PLoS Computational Biology, 
found that long fibres are important because they can send messages quickly 
over a longer distance compared with if the same message was sent over the 
same distance via lots of short fibres. It also found that long fibres are 
more reliable for transmission of messages over longer distances. 
"You can draw parallels with a train journey from Newcastle to London," said 
lead researcher, Dr Marcus Kaiser (pictured), of Newcastle University's 
School of Computing Science and the University's Institute of Neuroscience. 
"For example, you would get to London much more quickly and easily if you took 
a direct train there. However, if you had to make the journey via Durham, 
Leeds and Stevenage, changing trains each time, then it will take you longer 
to get there, and there is the possibility you would miss a connection at 
some point. It's the same in the human brain."
The computer programme, run over several days, took information about the 
length of nerve fibres in the primate brain and neuronal connections called 
axons in the brain of a species of worm known as Caenorhabditis elegans. It 
then tested if the total length of fibres could be reduced, by testing 
billions of different position arrangements. Indeed, wiring lengths could be 
reduced by up to 50% owing to the fact that neural systems have surprisingly 
many long-distance connections. 
Co-researcher Dr Claus Hilgetag, an associate professor with International 
University Bremen's School of Engineering and Science, said: "Many people 
have suggested that the brain is like a computer and that for optimum 
effectiveness it should have mainly short connections between the nerve 
cells. Our research suggests that a combination of different lengths of 
neural projections is essential.
"It is particularly interesting that we made the same observations in both the 
primate and the worm as their brains are very different in terms of shape and 
size."
Although it is too early for the research to have direct clinical 
applications, the researchers suggest that it may eventually contribute 
towards insights into the diagnosis and possibly the treatment of patients 
with Alzheimer's and autism if more information about neural networks - and 
specifically what the long and short nerve fibres do in the brain - is 
garnered. 
One potential development could be a predictive test for the conditions, which 
examines and analyses a patient's brain organisation, aiding diagnosis and 
possibly showing how the condition may develop over the coming years. 
The study is the most comprehensive yet to look at the spatial organisation of 
the nervous system in primates and worms. 
INTERVIEWS: 
Dr Marcus Kaiser, Newcastle University: +44 (0) 191 222 8161; 
[log in to unmask] Dr Claus C Hilgetag, International University Bremen: +49 
421 200 3542; [log in to unmask] 
SOURCE INFORMATION Citation: Kaiser M, Hilgetag CC (2006) Nonoptimal component 
placement, but short processing paths, due to long-distance projections in 
neural systems. PLoS Comput Biol 2(7): e95. DOI: 10.1371/journal.pcbi.0020095 
Freely accessible online at:  http://dx.doi.org/10.1371/journal.pcbi.0020095 
END OF PRESS RELEASE: Issued by Newcastle University Press Office. Contact 
Claire Jordan, Press Officer, tel. + 44 (0) 191 222 6067/7850 or email  
[log in to unmask] Press Office website:  www.ncl.ac.uk/press.office

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