title: Roles of ionic currents in lamprey CpG neurons: a modeling study.
abstract: The spinal network underlying locomotion in the lamprey consists of a core network of glutamatergic and glycinergic interneurons, previously studied experimentally and through mathematical modeling. We present a new and more detailed computational model of lamprey locomotor network neurons, based primarily on detailed electrophysiological measurements and incorporating new experimental findings. The model uses a Hodgkin-Huxley-like formalism and consists of 86 membrane compartments containing 12 types of ion currents. One of the goals was to introduce a fast, transient potassium current (K(t)) and two sodium-dependent potassium currents, one faster (K(NaF)) and one slower (K(NaS)), in the model. Not only has the model lent support to the interpretation of experimental results but it has also provided predictions for further experimental analysis of single-network neurons. For example, K(t) was shown to be one critical factor for controlling action potential duration. In addition, the model has proved helpful in investigating the possible influence of the slow afterhyperpolarization on repetitive firing during ongoing activation. In particular, the balance between the simulated slow sodium-dependent and calcium-dependent potassium currents has been explored, as well as the possible involvement of dendritic conductances.
authors.affiliation: School of Computer Science and Communication, Royal Institute of Technology, Stockholm, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Huss
authors.forename: Anders
authors.initials: A
authors.lastname: Lansner
authors.forename: Peter
authors.initials: P
authors.lastname: Wallén
authors.forename: Abdeljabbar
authors.initials: A
authors.lastname: El Manira
authors.forename: Sten
authors.initials: S
authors.lastname: Grillner
authors.forename: Jeanette H
authors.initials: JH
authors.lastname: Kotaleski
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000465:Algorithms; D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D066298:In Vitro Techniques; D007473:Ion Channels / Q000502:physiology*; D007700:Kinetics; D007798:Lampreys / Q000502:physiology*; D008564:Membrane Potentials / Q000502:physiology; D008959:Models, Neurological; D018721:Muscarinic Agonists / Q000494:pharmacology; D016571:Neural Networks, Computer; D009474:Neurons / Q000502:physiology* / Q000648:ultrastructure; D026902:Potassium Channel Blockers / Q000494:pharmacology; D015221:Potassium Channels / Q000502:physiology; D024681:Potassium Channels, Calcium-Activated / Q000502:physiology; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects; D012964:Sodium / Q000502:physiology; D019789:Tetraethylammonium / Q000494:pharmacology; D013779:Tetrodotoxin / Q000494:pharmacology
chemical_list: D007473:Ion Channels; D018721:Muscarinic Agonists; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D024681:Potassium Channels, Calcium-Activated; D016194:Receptors, N-Methyl-D-Aspartate; D013779:Tetrodotoxin; D019789:Tetraethylammonium; D002217:Carbachol; D012964:Sodium