Volume 11 Supplement 1
Calcium-dependent subthreshold fluctuations in membrane voltage; a modeling study
© Bardakjian et al; licensee BioMed Central Ltd. 2010
Published: 20 July 2010
Membrane potential noise plays multiple functional roles in the nervous system, as described in the review by Faisal et al. Calcium-dependent potassium (KCa) channels are ion channels whose conductance depends on intracellular calcium concentration. Previous work by Diba et al suggests that such channels play a central role in subthreshold voltage noise . While most channels generate noise through their inherent thermal fluctuations, we hypothesize that KCa channels also generate low-frequency subthreshold oscillations by transmitting stochastic fluctuations in intracellular calcium.
We have produced a stochastic computer model that incorporates KCa channels and calcium dynamics into a CA3 pyramidal neuron, which is based on the biophysically realistic Traub model . To introduce channel noise, we replaced all Hodgkin-Huxley (HH) channels with equivalent Markov models . There is also an intracellular calcium pool, with Ca2+ levels that vary stochastically due to influx through Markovian calcium channels.
- Faisal AA, Selen LPJ, Wolpert DM: Noise in the nervous system. Nature Reviews Neuroscience. 2008, 9 (4): 292-10.1038/nrn2258.PubMed CentralView ArticlePubMedGoogle Scholar
- Diba K, Lester HA, Koch C: Intrinsic noise in cultured hippocampal neurons: experiment and modeling. Journal of Neuroscience. 2004, 24 (43): 9723-10.1523/JNEUROSCI.1721-04.2004.View ArticlePubMedGoogle Scholar
- Traub RD, Jefferys JG, Miles R, Whittington MA, Toth K: A branching dendritic model of a rodent CA3 pyramidal neurone. J Physiol (Lond.). 1994, 481 (Pt1): 79.View ArticleGoogle Scholar
- Strassberg AF, DeFelice LJ: Limitations of the Hodgkin-Huxley formalism: Effects of single channel kinetics on transmembrane voltage dynamics. Neural Comput. 1993, 5 (6): 843-855. 10.1162/neco.19184.108.40.2063.View ArticleGoogle Scholar
This article is published under license to BioMed Central Ltd.