Failure of spinal cord serotonin depletion to alter analgesia elicited from the periaqueductal gray

Jan N. Johannessen, Linda R. Watkins, Susan M. Carlton, David J. Mayer

    Research output: Contribution to journalArticle

    40 Scopus citations


    The effects of spinal cord serotonin depletion or combined serotonin/norepinephrine depletion on analgesia elicited by electrical stimulation of, or morphine microinjection into, the periaqueductal gray, were tested. Spinal cord serotonin was depleted by intrathecal injection of 5,7-dihydroxytryptamine (5,7-DHT), preceded by systemic desipramine, while 5,7-DHT alone was used to deplete both norepinephrine and serotonin. Selective serotonin depletion had no effect on analgesia induced by either method at 24 h, 1 week, or 2 weeks after treatment. Depletion of both monoamines had no effect on stimulation produced analgesia 24 h and one week after treatment, but produced a slight attenuation 2 and 3 weeks after treatment. In contrast, depletion of both monoamines drastically attenuated morphine analgesia 24 h after treatment. The results are discussed in relation to multiple pain inhibitory pathways.

    Original languageEnglish (US)
    Pages (from-to)373-386
    Number of pages14
    JournalBrain Research
    Issue number2
    StatePublished - Apr 15 1982



    • 5,7-DHT
    • analgesia
    • descending inhibition
    • periaqueductal gray
    • serotonin
    • spinal cord

    ASJC Scopus subject areas

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

    Cite this