Spontaneous voltage oscillations and response dynamics of a Hodgkin-Huxley type model of sensory hair cells
1 Department of Physics and Astronomy, Neuroscience Program, Ohio University, Athens, OH 45701, USA
2 Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Str. 38, 01187 Dresden, Germany
3 Bernstein Center for Computational Neuroscience, Physics Department Humboldt University Berlin, Philippstr. 13, Haus 2, 10115 Berlin, Germany
4 School of Science, Beijing Institute of Technology, 100081 Beijing, People's Republic of China
5 Neuroscience Institute and Department of Mathematics and Statistics, Georgia State University, Atlanta, GA 30303, USA
The Journal of Mathematical Neuroscience 2011, 1:11 doi:10.1186/2190-8567-1-11Published: 31 October 2011
We employ a Hodgkin-Huxley-type model of basolateral ionic currents in bullfrog saccular hair cells for studying the genesis of spontaneous voltage oscillations and their role in shaping the response of the hair cell to external mechanical stimuli. Consistent with recent experimental reports, we find that the spontaneous dynamics of the model can be categorized using conductance parameters of calcium-activated potassium, inward rectifier potassium, and mechano-electrical transduction (MET) ionic currents. The model is demonstrated for exhibiting a broad spectrum of autonomous rhythmic activity, including periodic and quasi-periodic oscillations with two independent frequencies as well as various regular and chaotic bursting patterns. Complex patterns of spontaneous oscillations in the model emerge at small values of the conductance of Ca2+-activated potassium currents. These patterns are significantly affected by thermal fluctuations of the MET current. We show that self-sustained regular voltage oscillations lead to enhanced and sharply tuned sensitivity of the hair cell to weak mechanical periodic stimuli. While regimes of chaotic oscillations are argued to result in poor tuning to sinusoidal driving, chaotically oscillating cells do provide a high sensitivity to low-frequency variations of external stimuli.