The pre-Bötzinger complex and phase-spanning neurons in the adult rat

Brain Res. 1998 Nov 2;809(2):204-13. doi: 10.1016/s0006-8993(98)00872-5.

Abstract

To characterise respiratory neurons in the pre-Bötzinger complex of adult rats, extracellular recordings were made from 302 respiratory neurons in the ventral respiratory group of sodium pentobarbitone anaesthetised adult rats. Neurons were located 0 to 1.6 mm caudal to the facial nucleus, and ventral to the nucleus ambiguus. The pre-Bötzinger complex comprised expiratory neurons (22%, 22/100), inspiratory neurons (37%, 37/100) and phase-spanning neurons (41%, 41/100). In contrast, 80% (125/157) of Bötzinger neurons were expiratory, and 80% (36/45) of rostral ventral respiratory group neurons were inspiratory. Rostrocaudally, the pre-Bötzinger complex extended about 400 microns, starting at the caudal pole of the nucleus ambiguus compact formation. The pre-Bötzinger complex was also characterised by a predominance of propriobulbar neurons (81%, 13/16). Furthermore, 68% (33/48) of expiratory-inspiratory neurons found were located within the pre-Bötzinger complex. The variety of neuronal subtypes in the pre-Bötzinger complex, including many firing during the expiratory-inspiratory transition is consistent with the hypothesis that this nucleus plays a key role in respiratory rhythm generation in the adult rat.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / drug effects
  • Action Potentials / physiology
  • Age Factors
  • Animals
  • Axons / physiology
  • Electric Stimulation
  • Electrophysiology
  • Homocysteine / analogs & derivatives
  • Homocysteine / pharmacology
  • Medulla Oblongata / cytology*
  • Medulla Oblongata / physiology*
  • Motor Neurons / drug effects
  • Motor Neurons / physiology*
  • Motor Neurons / ultrastructure
  • Periodicity
  • Phrenic Nerve / cytology
  • Phrenic Nerve / physiology
  • Rats
  • Rats, Sprague-Dawley
  • Respiration*
  • Spinal Cord / cytology
  • Spinal Cord / physiology
  • Vagotomy

Substances

  • Homocysteine
  • homocysteic acid