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Intrathecally applied morphine inhibits nociceptive C fiber input to the primary somatosensory cortex (SI) of the rat

Kalliomäki, Jarkko ; Luo, Xiao Ling ; Yu, Yong Bei and Schouenborg, Jens LU (1998) In Pain 77(3). p.323-329
Abstract

Nociceptive C fiber input to SI in the halothane-nitrous oxide anesthetized rat was assessed by recording cortical field potentials evoked by noxious thermal cutaneous stimulation with CO2-laser pulses. Morphine topically applied onto the lumbar spinal cord produced a dose-dependent inhibition of nociceptive C fiber input from the hind paw to the contralateral SI. The inhibitory effect of morphine was reversed by naloxone. Potentials evoked by CO2-laser stimulation of the forepaw were unaffected by morphine applied on the lumbar cord, indicating that the effect of morphine was exerted at the segmental level. It is concluded that input from nociceptive C fibers to SI is relayed in the spinal cord and can be... (More)

Nociceptive C fiber input to SI in the halothane-nitrous oxide anesthetized rat was assessed by recording cortical field potentials evoked by noxious thermal cutaneous stimulation with CO2-laser pulses. Morphine topically applied onto the lumbar spinal cord produced a dose-dependent inhibition of nociceptive C fiber input from the hind paw to the contralateral SI. The inhibitory effect of morphine was reversed by naloxone. Potentials evoked by CO2-laser stimulation of the forepaw were unaffected by morphine applied on the lumbar cord, indicating that the effect of morphine was exerted at the segmental level. It is concluded that input from nociceptive C fibers to SI is relayed in the spinal cord and can be inhibited by spinal opioid receptor activation. The present method offers an interesting model of ascending nociceptive transmission to the cerebral cortex. Copyright (C) 1998 International Association for the Study of Pain. Published by Elsevier Science B.V.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Analgesia, Cerebral cortex, Evoked potential, Opioids, Pain, Somatosensory pathways
in
Pain
volume
77
issue
3
pages
323 - 329
publisher
Elsevier
external identifiers
  • scopus:0032168759
  • pmid:9808358
ISSN
0304-3959
DOI
10.1016/S0304-3959(98)00115-8
language
English
LU publication?
yes
id
9bf6a87d-7c23-4518-9fe0-a6d892684f93
date added to LUP
2019-06-25 16:17:15
date last changed
2020-01-13 02:07:15
@article{9bf6a87d-7c23-4518-9fe0-a6d892684f93,
  abstract     = {<p>Nociceptive C fiber input to SI in the halothane-nitrous oxide anesthetized rat was assessed by recording cortical field potentials evoked by noxious thermal cutaneous stimulation with CO<sub>2</sub>-laser pulses. Morphine topically applied onto the lumbar spinal cord produced a dose-dependent inhibition of nociceptive C fiber input from the hind paw to the contralateral SI. The inhibitory effect of morphine was reversed by naloxone. Potentials evoked by CO<sub>2</sub>-laser stimulation of the forepaw were unaffected by morphine applied on the lumbar cord, indicating that the effect of morphine was exerted at the segmental level. It is concluded that input from nociceptive C fibers to SI is relayed in the spinal cord and can be inhibited by spinal opioid receptor activation. The present method offers an interesting model of ascending nociceptive transmission to the cerebral cortex. Copyright (C) 1998 International Association for the Study of Pain. Published by Elsevier Science B.V.</p>},
  author       = {Kalliomäki, Jarkko and Luo, Xiao Ling and Yu, Yong Bei and Schouenborg, Jens},
  issn         = {0304-3959},
  language     = {eng},
  number       = {3},
  pages        = {323--329},
  publisher    = {Elsevier},
  series       = {Pain},
  title        = {Intrathecally applied morphine inhibits nociceptive C fiber input to the primary somatosensory cortex (SI) of the rat},
  url          = {http://dx.doi.org/10.1016/S0304-3959(98)00115-8},
  doi          = {10.1016/S0304-3959(98)00115-8},
  volume       = {77},
  year         = {1998},
}