Microinjection of morphine into nucleus reticularis paragigantocellularis of the rat: suppression of noxious-evoked activity of nucleus raphe magnus neurons

Mary M. Heinricher, J. Peter Rosenfeld

Research output: Contribution to journalArticle

11 Scopus citations


Microinjection of 1 μg of morphine into nucleus reticularis paragigantocellularis (Pgc) of anesthetized rats depressed both noxious-evoked and spontaneous activity of nociresponsive neurons in the nucleus raphe magnus (NRM). This effect was naloxone-reversible, and was not observed after control injections dorsal to Pgc. The percent change in spontaneous firing was significantly greater than the percent change in pinch-evoked firing. This reduction in NRM neuronal discharge may contribute to the antinociceptive effects produced by microinjection of morphine into Pgc.

Original languageEnglish (US)
Pages (from-to)388-391
Number of pages4
JournalBrain research
Issue number1-2
StatePublished - Dec 16 1985



  • analgesia
  • microinjection
  • morphine
  • nucleus raphe magnus
  • nucleus reticularis paragigantocellularis
  • pain

ASJC Scopus subject areas

  • Neuroscience(all)
  • Molecular Biology
  • Clinical Neurology
  • Developmental Biology

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