Modeling the effects of extracellular potassium on bursting properties in pre-Bötzinger complex neurons
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10827_2016_Article_594.pdf
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Author(s)
Bacak, Bartholomew J.
Molkov, Yaroslav I.
Segaran, Joshua R.
Date Issued
February 2016
Journal
Journal of Computational Neuroscience
Publisher
Springer US
Citation
Bacak, Bartholomew J., Joshua Segaran, and Yaroslav I. Molkov. “Modeling the Effects of Extracellular Potassium on Bursting Properties in Pre-Bötzinger Complex Neurons.” Journal of Computational Neuroscience 40.2 (2016): 231–245.
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Author's final manuscript
Abstract
There are many types of neurons that intrinsically generate rhythmic bursting activity, even when isolated, and these neurons underlie several specific motor behaviors. Rhythmic neurons that drive the inspiratory phase of respiration are located in the medullary pre-Bötzinger Complex (pre-BötC). However, it is not known if their rhythmic bursting is the result of intrinsic mechanisms or synaptic interactions. In many cases, for bursting to occur, the excitability of these neurons needs to be elevated. This excitation is provided in vitro (e.g. in slices), by increasing extracellular potassium concentration (K[subscript out]) well beyond physiologic levels. Elevated K[subscript out] shifts the reversal potentials for all potassium currents including the potassium component of leakage to higher values. However, how an increase in K[subscript out], and the resultant changes in potassium currents, induce bursting activity, have yet to be established. Moreover, it is not known if the endogenous bursting induced in vitro is representative of neural behavior in vivo. Our modeling study examines the interplay between K[subscript out], excitability, and selected currents, as they relate to endogenous rhythmic bursting. Starting with a Hodgkin-Huxley formalization of a pre-BötC neuron, a potassium ion component was incorporated into the leakage current, and model behaviors were investigated at varying concentrations of K[subscript out]. Our simulations show that endogenous bursting activity, evoked in vitro by elevation of K[subscript out], is the result of a specific relationship between the leakage and voltage-dependent, delayed rectifier potassium currents, which may not be observed at physiological levels of extracellular potassium.
MIT Department
Massachusetts Institute of Technology. Department of Brain and Cognitive Sciences
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Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.1007/s10827-016-0594-8
