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March 2, 2006

Axon Forest

A group of pyramidal cell axons as they simultaneously convey a burst of spikes from one cortical layer to another. The bits of "fire" depicted on the axons represent "spikes" of electrical activity that travel down the axon and carry information within the brain.

Despite the large number of cells pictured in this visualization, this would only be a small percentage of the total number of cells found in an actual cortex. The space between the axons would be filled with other axons, other types of neurons and other cell types such as glial cells. [One of 4 related images. See Next Image.] (Note: Please see "Special Restrictions," below, regarding the use of this image.)

More about this Image
This still image was derived from animations developed by Greg Hood, John Burkardt and Greg Foss of the Pittsburgh Supercomputing Center. The work contributed to the planetarium show "Gray Matters: The Brain Movie," which debuted in 1999 at the Carnegie Science Center in Pittsburgh, Pa. With the brain's neural structure projected on the 3-D space of the planetarium dome, "Gray Matters" offers an interactive, multimedia lesson in the science of the brain for children and adults.

"Gray Matters" was a collaboration among the Studio for Creative Inquiry at Carnegie Mellon University, the Center for the Neural Basis of Cognition and the Pittsburgh Supercomputing Center (PSC). The work was supported in part by a National Science Foundation (NSF) grant (97-05491).

In 1987, the PSC biomedical program, funded by the National Institutes of Health (NIH), became the first extramural biomedical supercomputing program in the country. Since then, with support from NIH's National Center for Research Resources, PSC has fostered exchange between PSC expertise in computational science and experts in biology and medicine to solve important problems in the life sciences.

With NSF support, PSC provides access to LeMieux, a 3,000 processor terascale system capable of 6 trillion computations per second. As of March 2003, with support from NIH and NSF, PSC has also installed two 16-processor HP GS-1280-based systems. Named "Jonas" and "Rachel" for famous Pittsburgh scientists Jonas Salk and Rachel Carson, these two shared memory systems with very high-memory bandwidth will be upgraded to larger systems.

In addition to training and access to computational resources, the biomedical group carries out research in structural biology, protein and nucleic-acid sequence analysis, computational neuroscience and microphysiology. In the latter fields, PSC staff work in developing and conducting research with widely used applications software, including MCell, NEOSIM and PGenesis. (Date of image: 1999)

Credit: Image courtesy Greg Hood, John Burkardt and Greg Foss; Pittsburgh Supercomputing Center

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Special Restrictions: Permission is granted to use this image for personal, educational or nonprofit/non-commercial purposes only. Permission to use this image in a manner not stated here must be obtained from the Pittsburgh Supercomputing Center via e-mail at or

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Images credited to the National Science Foundation, a federal agency, are in the public domain. The images were created by employees of the United States Government as part of their official duties or prepared by contractors as "works for hire" for NSF. You may freely use NSF-credited images and, at your discretion, credit NSF with a "Courtesy: National Science Foundation" notation.

Additional information about general usage can be found in Conditions.

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