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Study of central CO2 chemosensitivity using a combined Goldman–Hodgkin‐Katz (GHK) and Hodgkin‐Huxley (HH) type of model
Author(s) -
Cordovez Juan M,
Clausen Chris,
Moore Leon,
Solomon Irene
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.621.1
Subject(s) - chemistry , hodgkin–huxley model , kinetics , biophysics , membrane potential , intracellular , cellular model , gating , biological system , neuroscience , biochemistry , physics , biology , quantum mechanics , in vitro
Our previous work has focused on identifying putative mechanisms for explaining the differences in intracellular pH (pH i ) regulation in CO 2 chemosensitive versus non‐chemosensitive neurons using a mathematical model. The model incorporates the kinetics of the Na + , K + ‐ ATPase, Na + ‐ H + exchanger (NHE), anion exchanger (AE), and passive diffusion of ions, as described by the Goldman‐Hodgkin‐Katz (GHK) equation. Other studies using mathematical models to investigate central CO 2 chemoreception have focused on identifying ion channels responsible for the firing responses of putative CO 2 chemosensitive neurons. Parameters for this kind of model are generally based on invertebrate studies, and the kinetics of acid/base transporters are often simulated by a mathematical expression that fits experimental data rather than underlying chemical kinetics. To overcome this limitation, we have coupled our mathematical model with a Hodgkin‐Huxley (HH) type of model in order to combine the Na + and K + voltage‐gating mechanisms with the kinetics of transmembrane transporters and passive diffusion of ions. This approach links CO 2 signaling with neuronal firing and membrane potential responses. To evaluate the new GHK‐HH coupled model, we compare its behavior to that of a simple HH model and its ability to generate limit cycle oscillations ( e.g. , trains of actions potentials). Supported by NS04532