Ion concentration dynamics as a mechanism for neuronal bursting
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We describe a simple conductance-based model neuron that includes intra- and extracellular ion concentration dynamics and show that this model exhibits periodic bursting. The bursting arises as the fast-spiking behavior of the neuron is modulated by the slow oscillatory behavior in the ion concentration variables and vice versa. By separating these time scales and studying the bifurcation structure of the neuron, we catalog several qualitatively different bursting profiles that are strikingly similar to those seen in experimental preparations. Our work suggests that ion concentration dynamics may play an important role in modulating neuronal excitability in real biological systems.
KeywordsNeuron Potassium Sodium Ion concentration Burst Seizure Epilepsy
The authors would like to acknowledge the assistance of Jeremy Owen in creating Fig. 2. This work was supported by the Collaborative Research in Computational Neuroscience program at National Institutes of Health via grant R01-MH79502 (EB).
- 1.Hodgkin, A.L., Huxley, A.F.: A quantitative description of membrane current and its application to conduction and excitation in nerve. J. Physiol. 117(4), 500–544 (1952)Google Scholar
- 2.Frankenhaeuser, B., Hodgkin, A.L.: The after-effects of impulses in the giant nerve fibres of Loligo. J. Physiol. 131, 341–376 (1956)Google Scholar
- 3.Grafstein, B.: Mechanism of spreading cortical depression. J. Neurophysiol 19, 154–171 (1956)Google Scholar
- 4.Green, J.D.: The hippocampus. Phys. Rev. 44, 561–608 (1964)Google Scholar
- 6.Fröhlich, F., Bazhenov, M., Iragui-Madoz, V., Sejnowski, T.J.: Potassium dynamics in the epileptic cortex: new insights on an old topic. Neurosci. 14(5), 422–433 (2008)Google Scholar
- 16.Kager, H., Wadman, W.J., Somjen, G.G.: Simulated seizures and spreading depression in a neuron model incorporating interstitial space and ion concentrations. J. Neurophysiol. 84, 495–512 (2000)Google Scholar
- 17.Somjen, G.G.: Ions in the Brain. Oxford University Press, New York (2004)Google Scholar
- 21.Izhikevich, E.: Dynamical Systems in Neuroscience. MIT, Cambridge (2007)Google Scholar
- 28.Jensen, M.S., Yaari, Y.: Role of intrinsic burst firing, potassium accumulation, and electrical coupling in the elevated potassium model of hippocampal epilepsy. J. Neurophysiol. 77, 1224–1233 (1997)Google Scholar
- 30.Connors, B.W., Telfeian, A.E.: Dynamic properties of cells, synapses, circuits and seizures in neocortex. In: Williamson, P.D., et al. (eds.) Neocortical Epilepsies. Advances in Neurology, vol. 84, pp. 141–152 (2000)Google Scholar