title: Differential contribution of pacemaker properties to the generation of respiratory rhythms during normoxia and hypoxia.
abstract: Pacemaker neurons have been described in most neural networks. However, whether such neurons are essential for generating an activity pattern in a given preparation remains mostly unknown. Here, we show that in the mammalian respiratory network two types of pacemaker neurons exist. Differential blockade of these neurons indicates that their relative contribution to respiratory rhythm generation changes during the transition from normoxia to hypoxia. During hypoxia, blockade of neurons with sodium-dependent bursting properties abolishes respiratory rhythm generation, while in normoxia respiratory rhythm generation only ceases upon pharmacological blockade of neurons with heterogeneous bursting properties. We propose that respiratory rhythm generation in normoxia depends on a heterogeneous population of pacemaker neurons, while during hypoxia the respiratory rhythm is driven by only one type of pacemaker.
authors.affiliation: Department of Organismal Biology and Anatomy, The University of Chicago, Chicago, IL 60637, USA. jfpena@mail.cinvestav.mx
authors.forename: Fernando
authors.initials: F
authors.lastname: Peña
authors.forename: Marjorie A
authors.initials: MA
authors.lastname: Parkis
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Tryba
authors.forename: Jan-Marino
authors.initials: JM
authors.lastname: Ramirez
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D001683:Biological Clocks / Q000187:drug effects / Q000502:physiology*; D002104:Cadmium / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D005260:Female; D005439:Flufenamic Acid / Q000494:pharmacology; D058787:GABA-A Receptor Antagonists; D002534:Hypoxia, Brain / Q000503:physiopathology*; D066298:In Vitro Techniques; D007811:Lanthanum / Q000494:pharmacology; D008297:Male; D008526:Medulla Oblongata / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D009415:Nerve Net / Q000187:drug effects / Q000502:physiology*; D010507:Periodicity; D011963:Receptors, GABA-A / Q000378:metabolism; D018009:Receptors, Glycine / Q000037:antagonists & inhibitors / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000378:metabolism; D012119:Respiration / Q000187:drug effects*; D012125:Respiratory Center / Q000187:drug effects / Q000502:physiology*; D019782:Riluzole / Q000494:pharmacology; D026941:Sodium Channel Blockers / Q000494:pharmacology; D015222:Sodium Channels / Q000187:drug effects / Q000502:physiology; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology
chemical_list: D058787:GABA-A Receptor Antagonists; D011963:Receptors, GABA-A; D018009:Receptors, Glycine; D016194:Receptors, N-Methyl-D-Aspartate; D026941:Sodium Channel Blockers; D015222:Sodium Channels; D002104:Cadmium; D005439:Flufenamic Acid; D007811:Lanthanum; D019782:Riluzole