title: A model of the rat phrenic motor neuron.
abstract: We have developed a model for the rat phrenic motor neuron (PMN) that robustly replicates many experimentally observed behaviors of PMNs in response to pharmacological, ionic, and electrical perturbations using a single set of parameters. Our model suggests that the after-depolarization (ADP) response seen in action potentials is a result of the slow deactivation of the fast sodium channel in the range of the ADP coupled with the activation of the L-type calcium channel (I(CaL)). This current and its interactions with the small and large conductance calcium-activated potassium currents (I(KCaSK) and I(KCaBK), respectively) is also important in the generation of spike frequency adaptation in the repetitive firing mode of activity. Other aspects of the model conform very well to experimental observations in both the action potential and repetitive firing mode of activity, including the role of I(KCaSK) in the medium after-hyperpolarization (AHP) and the role of I(KCaBK) in the fast AHP. We have made a number of predictions using the model, including the characterization of two putative sodium currents (fast and persistent), as well as functional roles for the N- and T-type calcium currents.
authors.affiliation: Department of Neurobiology and Anatomy, University of Texas Health Science Center at Houston, Houston, TX 77030, USA. Behrang.Amini@uth.tmc.edu
authors.forename: Behrang
authors.initials: B
authors.lastname: Amini
authors.forename: Akhil
authors.initials: A
authors.lastname: Bidani
authors.forename: Joseph B
authors.initials: JB
authors.lastname: Zwischenberger
authors.forename: John W
authors.initials: JW
authors.lastname: Clark
mesh_terms: D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology; D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D015640:Ion Channel Gating / Q000187:drug effects / Q000502:physiology; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D008959:Models, Neurological; D009046:Motor Neurons / Q000187:drug effects / Q000502:physiology*; D010791:Phrenic Nerve / Q000187:drug effects / Q000502:physiology*; D024681:Potassium Channels, Calcium-Activated / Q000187:drug effects / Q000502:physiology; D051381:Rats
chemical_list: D024681:Potassium Channels, Calcium-Activated; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester