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Functional homeostatic‐excitable cell model for CO2 chemosensing
Author(s) -
Cordovez Juan,
Quintero Maria Carolina,
Solomon Irene C
Publication year - 2011
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.25.1_supplement.lb636
Subject(s) - biological system , hodgkin–huxley model , steady state (chemistry) , conductance , neuroscience , computer science , physics , control theory (sociology) , chemistry , biophysics , biology , artificial intelligence , control (management) , condensed matter physics
Work from our laboratory has focused on developing a comprehensive mathematical model of central respiratory CO2 chemoreceptors that considers the homeostatic response of the cell an important factor for transduction of the signal(s) into a change in firing rate. A distinctive feature of our model, and prerequisite for studying cellular functions in addition to the electrical response, is that fluxes are described by the permeability‐based Goldman‐Hodgkin‐Katz (GHK) equation as opposed to a typical conductance‐based Hodgkin‐Huxley (HH) approach. Since experimental measurements of permeability are rare, we employ theoretical approaches to estimate parameters for each ion channel incorporated into our model. Our model behavior is then compared to that of a published comparable HH model. Approaches implemented include fitting simulated voltage‐clamp experiments, steady‐state I‐V curves, and least squares analysis. Here, we isolate voltage‐sensitive Na+ current and delayed‐rectifier K+ current to form a minimal model for excitability and explore its dynamical features (i.e., stability, bifurcations). Implementation of this approach demonstrates that our GHK model yields a richer dynamical response than the HH model. We propose that this approach be used to generate more realistic models for studies of neuronal excitability in mammalian CO2 chemoreceptors. Supported by NS045321 and HL63175.