Navigation Links
The brain's connectome -- from branch to branch
Date:7/28/2011

This release is available in German.

The human brain is the most complex of all organs, containing billions of neurons with their corresponding projections, all woven together in a highly complex, three-dimensional web. To date, mapping this vast network posed a practically insurmountable challenge to scientists. Now, however, a research team from the Heidelberg-based Max Planck Institute for Medical Research has developed a method for tackling the mammoth task. Using two new computer programs, KNOSSOS and RESCOP, a group of over 70 students mapped a network of more than 100 neurons and they did so faster and more accurately than with previous methods.

With some 70 billion neurons and hundreds of thousands of kilometres of circuits, the human brain is so complex that, for many years, it seemed impossible to reconstruct the network in detail. Each neuron is linked to about a thousand others by means of finely branched projections called dendrites and axons, and communicates with them using electrical signals. The connections between the cells are critical for brain function, so neuroscientists are keen to understand the structure of these circuits the connectome and to reconstruct it in a three-dimensional map. Since no computer is powerful enough yet for the task, researchers are dependent on the human eye. However, the sheer number of cellular connections contained in even the tiniest fragment of tissue makes the undertaking seem pointless unless it is shared among a large number of people.

Moritz Helmstaedter, Kevin L. Briggman and Winfried Denk, scientists at the Max Planck Institute for Medical Research in Heidelberg, have now successfully tested this procedure. They developed a special software tool called RESCOP which summarises the results of several annotators to yield an overall picture. In this way, and with the support of over 70 students from Heidelberg University, they reconstructed a network of over 100 neurons from the retina in full detail.

The students used the KNOSSOS software developed by the team in Heidelberg to trace the connections between the neurons. It is no coincidence that the program is named after Crete's legendary palace, renowned for its elaborate labyrinth: "Tracing the connections in the brain is at least as hard as finding your way out of a mythological labyrinth", explains Moritz Helmstaedter.

In order to reconstruct a neural circuit, researchers start by staining the neurons of a section of tissue with heavy metals to make them visible. Using three-dimensional electron microscope images, they start at the cell body and follow the dendrites and axons, marking the branch point nodes on the screen. Then they use the computer to generate a three-dimensional image of the section. In this way, they work their way through the tangle of neurons bit by bit. It is a tedious undertaking: One person working alone with the currently available programs would take at least 30 years to reconstruct a path of 30 centimetres in length. Besides, these procedures are prone to error, since the branch points are not always easily recognised and the annotator's attentiveness decreases with time.

The KNOSSOS software considerably reduces the time required: It is about 50 times faster than other programs used up to now. In addition, the RESCOP program now makes it possible for dozens of people to work on the reconstruction at the same time. Since the method is easily learned, even non-experts can use it. Most of the students worked from home and sent their results to the scientists via e-mail. The scientists were able to establish that the error rate of the best students was no higher than that of experienced neurobiologists. Moreover, its sophisticated algorithms enable RESCOP to detect and average out inaccuracies. This means that the reconstruction is not only faster, but also more reliable than before.

"For the first time ever, these new programs could make it possible for us to unravel the complicated neural network of the brain a task far more complex than decoding the human genome", says Winfried Denk. Next, the scientists plan to reconstruct a fragment of the mouse cerebral cortex, as this is where all the important mental processes occur.


'/>"/>

Contact: Dr. Moritz Helmstaedter
moritz.helmstaedter@mpimf-heidelberg.mpg.de
49-622-148-6149
Max-Planck-Gesellschaft
Source:Eurekalert  

Related medicine news :

1. Pro Athletes Brains React at Olympic Speed
2. iPhone Memory Aid for Scatterbrains, Aging Baby Boomers and Busy, Forgetful People
3. MessageSolution First in the Market to Offer All-in-One, Integrated Cloud-Based Archiving for Email, File Systems and SharePoint at Novell BrainShare 2010
4. Scientists Tweak Subjects Brains to Alter Their Moral Choices
5. SharpBrains Launches First Brain Fitness Innovation Awards to Recognize Neuroplasticity Pioneers
6. Morphine May Protect Brains of People With HIV
7. SKyPRO Releases Public Beta of GWTalk at BrainShare
8. Blood flows differently through the brains of schizophrenic patients
9. Adolescent brains biologically wired to engage in risky behavior, study finds
10. Gay mens bilateral brains better at remembering faces: York U study
11. Tool manipulation is represented similarly in the brains of the blind and the sighted
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
The brain's connectome -- from branch to branch
(Date:5/26/2016)... ... , ... Development Team of Pixel Film Studios Announced The Release of TranSweep, ... transition tool will keep a consistent flow to your project while adding interesting visuals ... TranSweep is an all new layered style transition tool for Final Cut Pro ...
(Date:5/26/2016)... , ... May 26, 2016 , ... In Madeira Beach ... mainland by a single drawbridge, citizens formed an organization, Madeira Beach United, to oppose ... and change the small town center to a high rise urban environment. , According ...
(Date:5/26/2016)... ... 2016 , ... According to the Webster’s dictionary, a hippie is defined as ... one company is going against the norm with a line of all-natural skincare that’s ... the green space is proud to announce its latest retail partnership with the Vitamin ...
(Date:5/26/2016)... California (PRWEB) , ... May 26, 2016 , ... ... Barbara this Memorial Day weekend to host their second pop-up shop for three ... Diego fashion forward brand to the Santa Barbara community, a community full of ...
(Date:5/26/2016)... Malvern, PA (PRWEB) , ... May 26, 2016 ... ... Sharon Wolf has been hired as FluidEdge’s Vice President of Business Intelligence and ... health analytics, Wolf has demonstrated success leading teams as a healthcare business and ...
Breaking Medicine News(10 mins):
(Date:5/25/2016)... 2016  According to Kalorama Information, the world ... 2015.  Though these are challenging times in the ... success for companies that remain optimistic and seek ... growth prospects medical device companies spend a higher ... (R&D) than do companies in other industries.  Also, ...
(Date:5/25/2016)... PARIS , May 25, 2016 ... system disorders, announces that an oral presentation entitled "High doses ... the MS-SPI trial" will be given by Professor Ayman ... the 2nd Congress of the European Academy of Neurology (EAN) ... "MS and related disorders 3" will take place on Sunday, ...
(Date:5/24/2016)...   , ... primären Endpunkte und demonstriert Ebenbürtigkeit bei der Gesamtreinigung ... plus guter , Reinigung des ...      (Logo: http://photos.prnewswire.com/prnh/20130829/633895-a ) , ... von der MORA-Studie der Phase III für NER1006 ...
Breaking Medicine Technology: