Navigation Links
Web-crawling the brain
Date:3/9/2011

BOSTON, Mass. (March 9, 2011) The brain is a black box. A complex circuitry of neurons fires information through channels, much like the inner workings of a computer chip. But while computer processors are regimented with the deft economy of an assembly line, neural circuits are impenetrable masses. Think tumbleweed.

Researchers in Harvard Medical School's Department of Neurobiology have developed a technique for unraveling these masses. Through a combination of microscopy platforms, researchers can crawl through the individual connections composing a neural network, much as Google crawls Web links.

"The questions that such a technique enables us to address are too numerous even to list," said Clay Reid, HMS professor of neurobiology and senior author on a paper reporting the findings in the March 10 edition of Nature.

The cerebral cortex is arguably the most important part of the mammalian brain. It processes sensory input, reasoning and, some say, even free will. For the past century, researchers have understood the broad outline of cerebral cortex anatomy. In the past decade, imaging technologies have allowed us to see neurons at work within a cortical circuit, to watch the brain process information.

But while these platforms can show us what a circuit does, they don't show us how it operates.

For many years, Reid's lab has been studying the cerebral cortex, adapting ways to hone the detail with which we can view the brain at work. Recently they and others have succeeded in isolating the activities of individual neurons, watching them fire in response to external stimuli.

The ultimate prize, however, would be to get inside a single cortical circuit and probe the architecture of its wiring.

Just one of these circuits, however, contains between 10,000 and 100,000 neurons, each of which makes about 10,000 interconnections, totaling upwards of 1 billion connectionsall within a single circuit. "This is a radically hard problem to address," Reid said.

Reid's team, which included Davi Bock, then a graduate student, and postdoctoral researcher Wei-Chung Allen Lee, embarked on a two-part study of the pinpoint-sized region of a mouse brain that is involved in processing vision. They first injected the brain with dyes that flashed whenever specific neurons fired and recorded the firings using a laser-scanning microscope. They then conducted a large anatomy experiment, using electron microscopy to see the same neurons and hundreds of others with nanometer resolution.

Using a new imaging system they developed, the team recorded more than 3 million high-resolution images. They sent them to the Pittsburgh Supercomputing Center at Carnegie Mellon University, where researchers stitched them into 3-D images. Using the resulting images, Bock, Lee and laboratory technician Hyon Suk Kim selected 10 individual neurons and painstakingly traced many of their connections, crawling through the brain's dense thicket to create a partial wiring diagram.

This model also yielded some interesting insights into how the brain functions. Reid's group found that neurons tasked with suppressing brain activity seem to be randomly wired, putting the lid on local groups of neurons all at once rather than picking and choosing. Such findings are important because many neurological conditions, such as epilepsy, are the result of neural inhibition gone awry.

"This is just the iceberg's tip," said Reid. "Within ten years I'm convinced we'll be imaging the activity of thousands of neurons in a living brain. In a visual circuit, we'll interpret the data to reconstruct what an animal actually sees. By that time, with the anatomical imaging, we'll also know how it's all wired together."

For now, Reid and his colleagues are working to scale up this platform to generate larger data sets.

"How the brain works is one of the greatest mysteries in nature," Reid added, "and this research presents a new and powerful way for us to explore that mystery."


'/>"/>

Contact: David Cameron
david_cameron@hms.harvard.edu
617-432-0441
Harvard Medical School
Source:Eurekalert

Related biology technology :

1. Stemline Therapeutics Licenses Phase I/II Brain Cancer Vaccine - Shows Promise in Clinical Trial Conducted at University of Pittsburgh
2. New Pitt projects will test brain computer interfaces for people with spinal cord injury
3. Taking brain-computer interfaces to the next phase
4. Some brain tumors mimic the genetic program of germline cells
5. Ceregene Reports New Findings Regarding How Parkinsons Brains Respond to Neurotrophic Factors
6. New Method of Nutrition to Permanently Protect Brain Cells from Genetic Damage
7. Robot arm improves performance of brain-controlled device
8. Virtual reality helps researchers track how brain responds to surroundings
9. Neuro-Biotech Corp. Neuroceuticals® : A solution to feed the brain
10. Boston Scientific Begins Patient Enrollment in Clinical Trial Assessing Deep Brain Stimulation for Parkinsons Disease
11. Stone Age humans needed more brain power to make big leap in tool design
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/9/2016)... PA (PRWEB) , ... February 09, 2016 , ... With ... the 2016 Wharton Health Care Business Conference will bring together over 500 top healthcare ... for an industry in transformation. The conference, organized by MBA students of the University ...
(Date:2/9/2016)... ... February 09, 2016 , ... Tunnell Consulting, Inc. announced that Frédéric Lefebvre has ... focus on acquiring new accounts and work closely with existing Tunnell clients throughout Europe ... to our European clients more than 15 years of experience in the pharmaceutical industry, ...
(Date:2/9/2016)... , Feb. 9, 2016 This market ... the current and future prospects of the market in ... report include companies engaged in the manufacture of microbiology ... executive summary with a market snapshot providing the overall ... of this report. This section also provides the overall ...
(Date:2/8/2016)... , Feb. 8, 2016 /PRNewswire/ - BIOREM Inc. (TSXV: ... the top ten finalists for clean technology companies in the ... the top 10 companies listed on the TSX Venture Exchange, ... & gas, clean technology & life sciences, diversified ... equal weighting given to return on investment, market cap growth, ...
Breaking Biology Technology:
(Date:1/25/2016)... Jan. 25, 2016  Glencoe Software, the world-leading supplier ... publication industries, will provide the data management solution OMERO ... Photo ... Phenotypic analysis measures the characteristics ... allowing comparisons between states such as health and disease, ...
(Date:1/20/2016)... 20, 2016   MedNet Solutions , an innovative ... of clinical research, is pleased to announce the attainment ... are the result of the company,s laser focus on ... , it,s comprehensive, easy-to-use and highly affordable cloud-based ... Key MedNet growth achievements in 2015 include: ...
(Date:1/13/2016)... January 13, 2016 ... addition of the  "India Biometrics Authentication ... Forecast (2015-2020)"  report to their ... has announced the addition of the  ... - Estimation & Forecast (2015-2020)" ...
Breaking Biology News(10 mins):