Researchers have found the first evidence that chemical activity within networks of brain cells displays behavior that is characteristic of self-organized criticality. Previously seen only in physical processes, self-organized criticality describes complex systems far from equilibrium that spontaneously move toward a critical state without external tuning.

While the implications of the work remain unclear, the researchers believe further study could lead to new insights into disease processes, improved techniques for diagnosing diseases of the brain, and perhaps even new treatment options. Modelling techniques developed for the work could also give neuroscientists a new way to study long-range signalling in the brain.

"This work makes a connection between physics -- where we understand self-organized criticality -- and complex biological systems," said Dr. Peter Jung, a visiting physicist at the Georgia Institute of Technology. "It is a starting point for a complete new way of thinking about waves in the brain and disease processes."

Jung and Dr. Ann Cornell-Bell of Connecticut-based Viatech Imaging, combined theoretical modeling with experimental observation of chemical activity in cells taken from the hippocampal area of a rat brain. Their collaboration began after another researcher, Dr. Frank Moss from the University of Missouri at St. Louis, noticed similarities between calcium ion waves that Cornell-Bell observed and mathematical models of noise-enhanced pattern formation developed by Jung.

Development of Imbalance Makes Waves More Likely

The calcium ion waves studied by Jung, Cornell-Bell, Moss and collaborator Dr. Kathleen Shaver Madden arise randomly in brain cells known as astrocytes, whose normal task is to regulate the flow of ions and neurotransmitters in the neuronal cells that transmit signals in the brain. The astrocytes can become chemical
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Contact: John Toon
john.toon@gtri.gatech.edu
404-894-6986
Georgia Institute of Technology Research News
6-Jun-1997