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:5/26/2017)... MA (PRWEB) , ... May 26, 2017 , ... On ... Act (AHCA), which narrowly passed the U.S. House on May 4, would result in ... be expected under continued implementation of the 2010 Patient Protection and Affordable Care Act ...
(Date:5/26/2017)... , ... May 26, 2017 , ... Dr. Alex Rabinovich, ... to announce a new, informational blog post on insurance options. If a Bay Area ... plans may help save time and money. Visiting an in-network provider for a second ...
(Date:5/26/2017)... ... ... “Cactus Jack: Against All Odds”: the story of Coach Cactus Jack and the ... is the creation of published author, Walter Hubbard, a retired wildlife and fisheries biologist ... Jane. Walter. Walter and Jane have three adult children and a granddaughter. ...
(Date:5/24/2017)... ... May 24, 2017 , ... Altec Products, Inc., a leader in ... a one-day technology conference in San Diego, CA. , At nVerge 2017, Altec ... fully utilize and enhance their Sage ERP solutions by providing improved visibility and control ...
(Date:5/24/2017)... Washington, DC (PRWEB) , ... May 24, 2017 ... ... The Center for Global Policy Solutions is vehemently opposed to Donald Trump’s budget, ... old formula for despair that inspires fear, demonizes the poor, marginalizes underserved populations, ...
Breaking Medicine News(10 mins):
(Date:5/9/2017)... 9, 2017 Zimmer Biomet Holdings, Inc. (NYSE ... today announced it has earned a spot on ... The Company was ranked among 500 U.S. employers as ... Healthcare Equipment and Services. The annual ... anonymous, independent survey of over 30,000 employees across 25 ...
(Date:5/8/2017)... May 8, 2017  Diplomat Pharmacy, Inc. (NYSE: DPLO)., ... ("WRB"), a health care service center company based ... WRB specializes in relationship management programs for leading pharmaceutical ... WRB will join Envoy Health ... services for manufacturers, biotech firms, and other service companies. ...
(Date:5/4/2017)... 4, 2017  A recent study published in ... Ultraviolet-C light as a means of disinfection anesthesia ... reduce bioburden on anesthesia workstations. In the study, ... complex medical equipment surfaces contaminated with three (3) ... "This study further validates the body of literature ...
Breaking Medicine Technology: