Parabrachial-lateral pontine neurons link nociception and breathing

Respir Physiol Neurobiol. 2004 Nov 15;143(2-3):215-33. doi: 10.1016/j.resp.2004.07.019.

Abstract

We investigated the role of the parabrachial complex in cutaneous nociceptor-induced respiratory stimulation in chloralose-urethane anesthetized, vagotomized rats. Noxious stimulation (mustard oil, MO) applied topically to a forelimb or hindlimb enhanced the peak amplitude of the integrated phrenic nerve discharge and, with forelimb application, increased phrenic nerve burst frequency. Bilateral inactivation of neural activity in the parabrachial complex with injection of the GABA agonist muscimol (3nl) markedly attenuated the response to MO application. Injection of the retrograde tracer FluoroGold within the medullary ventral respiratory column labeled neurons in dorsolateral pontine regions known to receive nociceptive inputs (i.e., Kolliker-Fuse, lateral crescent, and superior lateral subnuclei of the parabrachial complex). Extracellular recordings of 65 dorsolateral parabrachial neurons revealed about 15% responded to a noxious cutaneous pinch with either an increase or a decrease in discharge and approximately 40% of these exhibited a phasic respiratory-related component to their discharge. In conclusion, parabrachial pontine neurons contribute to cutaneous nociceptor-induced increases in breathing.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Action Potentials / drug effects
  • Action Potentials / physiology
  • Animals
  • Brain Mapping
  • Drug Administration Schedule
  • Extremities / innervation
  • Extremities / radiation effects
  • Fluorescent Dyes / metabolism
  • GABA Agonists / pharmacology
  • Male
  • Medulla Oblongata / cytology
  • Medulla Oblongata / drug effects
  • Medulla Oblongata / physiology*
  • Medulla Oblongata / physiopathology
  • Muscimol / pharmacology
  • Mustard Plant
  • Neural Pathways / drug effects
  • Neural Pathways / physiology
  • Neural Pathways / physiopathology*
  • Neurons / physiology*
  • Pain / chemically induced
  • Pain / physiopathology*
  • Pain Measurement / methods
  • Phrenic Nerve / drug effects
  • Phrenic Nerve / physiopathology
  • Physical Stimulation / methods
  • Pons / cytology*
  • Pons / physiology
  • Rats
  • Rats, Sprague-Dawley
  • Respiration*
  • Staining and Labeling / methods
  • Stilbamidines / metabolism
  • Vagotomy / methods

Substances

  • 2-hydroxy-4,4'-diamidinostilbene, methanesulfonate salt
  • Fluorescent Dyes
  • GABA Agonists
  • Stilbamidines
  • Muscimol