Antinociception induced by electrical stimulation of spinally projecting noradrenergic neurons in the A7 catecholamine cell group of the rat

David C. Yeomans, Frank M. Clark, Judith A. Paice, Herbert K. Proudfit*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

102 Scopus citations

Abstract

Recent anatomical evidence indicates that the pontine A7 catecholamine cell group provides the major noradrenergic innervation of the spinal cord dorsal horn (laminae I-IV). The experiments described in this report were designed to determine if these neurons modulate nociception at the level of the spinal cord. To this end, the antinociceptive effect of electrical stimulation applied at various sites along several tracks through the dorsolateral pontine tegmentum was determined in lightly anesthetized rats. The latency of the withdrawal response of the hind feet to noxious radiant thermal stimulation applied to the dorsal surface was used as a measure of nociception. The results indicated that the most potent and consistent antinociception was produced at sites near the A7 cell group. In addition, intrathecal injection of α-noradrenergic antagonists blocked the antinociception produced by electrical stimulation at sites near the A7 group. These observations indicate that the antinociception produced by stimulation near the A7 cell group was mediated by spinally projecting noradrenergic neurons. The results of these experiments provide evidence that pontospinal noradrenergic neurons located in the A7 cell group are important components of the descending neuronal system that modulates nociception.

Original languageEnglish (US)
Pages (from-to)449-461
Number of pages13
JournalPain
Volume48
Issue number3
DOIs
StatePublished - Mar 1992

Keywords

  • A7 cell group
  • Norepinephrine
  • Phentolamine
  • Spinal cord
  • Yohimbine
  • α-adrenoceptors

ASJC Scopus subject areas

  • Neurology
  • Clinical Neurology
  • Anesthesiology and Pain Medicine

Fingerprint Dive into the research topics of 'Antinociception induced by electrical stimulation of spinally projecting noradrenergic neurons in the A7 catecholamine cell group of the rat'. Together they form a unique fingerprint.

Cite this