Respiratory rhythm: an emergent network property?

Neuron. 2002 May 30;34(5):821-30. doi: 10.1016/s0896-6273(02)00712-2.

Abstract

We tested the hypothesis that pacemaker neurons generate breathing rhythm in mammals. We monitored respiratory-related motor nerve rhythm in neonatal rodent slice preparations. Blockade of the persistent sodium current (I(NaP)), which was postulated to underlie voltage-dependent bursting in respiratory pacemaker neurons, with riluzole (< or =200 microM) did not alter the frequency of respiratory-related motor output. Yet, in every pacemaker neuron recorded (50/50), bursting was abolished at much lower concentrations of riluzole (< or =20 microM). Thus, eliminating the pacemaker population (our statistics confirm that this population is reduced at least 94%, p < 0.05) does not affect respiratory rhythm. These results suggest that voltage-dependent bursting in pacemaker neurons is not essential for respiratory rhythmogenesis, which may instead be an emergent network property.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Action Potentials / drug effects
  • Action Potentials / physiology
  • Animals
  • Animals, Newborn
  • Biological Clocks / drug effects
  • Biological Clocks / physiology
  • Cell Differentiation / drug effects
  • Cell Differentiation / physiology
  • Cell Membrane / drug effects
  • Cell Membrane / physiology
  • Dose-Response Relationship, Drug
  • Efferent Pathways / drug effects
  • Efferent Pathways / growth & development*
  • Efferent Pathways / physiology
  • Excitatory Amino Acid Antagonists / pharmacology
  • Hypoglossal Nerve / drug effects
  • Hypoglossal Nerve / physiology
  • Medulla Oblongata / drug effects
  • Medulla Oblongata / growth & development*
  • Medulla Oblongata / physiology
  • Mice
  • Nerve Net / drug effects
  • Nerve Net / growth & development*
  • Nerve Net / physiology
  • Neurons / drug effects
  • Neurons / physiology*
  • Organ Culture Techniques
  • Periodicity
  • Rats
  • Respiration / drug effects*
  • Respiratory Center / drug effects
  • Respiratory Center / growth & development*
  • Respiratory Center / physiology
  • Riluzole / pharmacology
  • Sodium Channels / drug effects
  • Sodium Channels / physiology
  • Spinal Cord / drug effects
  • Spinal Cord / growth & development*
  • Spinal Cord / physiology
  • Synaptic Transmission / drug effects
  • Synaptic Transmission / physiology

Substances

  • Excitatory Amino Acid Antagonists
  • Sodium Channels
  • Riluzole