1471-2202-9-S1-O9 1471-2202 Oral presentation <p>Ion concentration dynamics: mechanisms for bursting and seizing</p> Cressman JR jcressma@gmu.edu Ullah G ghanim@psu.edu Ziburkus J jziburku@Central.uh.edu Schiff SJ sjs49@engr.psu.edu Barreto E ebarreto@gmu.edu

Department of Physics & Astronomy and The Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia, 22030, USA

Department of Engineering Sciences and Mechanics, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA

Department of Biology and Biochemistry, The University of Houston, Houston, Texas, USA

Departments of Neurosurgery and Physics, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA

 BMC Neuroscience <p>Seventeenth Annual Computational Neuroscience Meeting: CNS*2008</p> William R Holmes Publication of this supplement was sponsored by Royal Society Publishing, Neuralynx, Springer, MIT Press and National Bernstein Network for Computational Neuroscience Meeting abstracts – A single PDF containing all abstracts in this Supplement is available here. http://www.biomedcentral.com/content/pdf/1471-2202-9-S1-info.pdf <p>Seventeenth Annual Computational Neuroscience Meeting: CNS*2008</p> Portland, OR, USA 19–24 July 2008 http://www.cnsorg.org/ 1471-2202 2008 9 Suppl 1 O9 http://www.biomedcentral.com/1471-2202/9/S1/O9 10.1186/1471-2202-9-S1-O9 11 7 2008 2008 Cressman et al; licensee BioMed Central Ltd.

The Hodgkin-Huxley equations are of fundamental importance in theoretical neuroscience. However, these equations assume that the intra- and extra-cellular ion concentrations of sodium and potassium are constant. While this is a reasonable assumption for the squid giant axon preparation, its validity in other cases, especially in mammalian brain, is subject to debate. It is therefore surprising that relatively little attention has been paid to the dynamics of ion concentrations in the years since Hodgkin and Huxley's seminal work was published. We develop a conductance-based model neuron that includes intra- and extra-cellular ion concentration dynamics. We further formulate a reduction of this model to identify the bifurcation structure. Using these models, we describe novel mechanisms for bursting and seizing behavior that is strikingly similar to that seen in experimental preparations.