Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2002-5-7
pubmed:abstractText
A direct action of mu-opioid agonists on neurons in the spinal dorsal horn is thought to contribute to opiate-induced analgesia. In this study we have investigated neurons that express the mu-opioid receptor MOR-1 in rat spinal cord to provide further evidence about their role in nociceptive processing. MOR-1-immunoreactive cells were largely restricted to lamina II, where they comprised approximately 10% of the neuronal population. The cells received few contacts from nonpeptidergic unmyelinated afferents, but many from substance P-containing afferents. However, electron microscopy revealed that most of these contacts were not associated with synapses. None of the MOR-1 cells in lamina II expressed the neurokinin 1 receptor; however, the mu-selective opioid peptide endomorphin-2 was present in the majority (62-82%) of substance P axons that contacted them. Noxious thermal stimulation of the foot induced c-Fos expression in approximately 15% of MOR-1 cells in the medial third of the ipsilateral dorsal horn at mid-lumbar level. However, following pinching of the foot or intraplantar injection of formalin very few MOR-1 cells expressed c-Fos, and for intraplantar formalin injection this result was not altered significantly by pretreatment with systemic naloxone. Although these findings indicate that at least some of the neurons in lamina II with MOR-1 are activated by noxious thermal stimulation, the results do not support the hypothesis that the cells have a role in transmitting nociceptive information following acute mechanical or chemical noxious stimuli.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0953-816X
pubmed:author
pubmed:issnType
Print
pubmed:volume
15
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1306-16
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:11994125-Afferent Pathways, pubmed-meshheading:11994125-Animals, pubmed-meshheading:11994125-Cell Communication, pubmed-meshheading:11994125-Female, pubmed-meshheading:11994125-Hot Temperature, pubmed-meshheading:11994125-Hyperalgesia, pubmed-meshheading:11994125-Male, pubmed-meshheading:11994125-Nerve Fibers, pubmed-meshheading:11994125-Nociceptors, pubmed-meshheading:11994125-Oligopeptides, pubmed-meshheading:11994125-Pain, pubmed-meshheading:11994125-Posterior Horn Cells, pubmed-meshheading:11994125-Presynaptic Terminals, pubmed-meshheading:11994125-Proto-Oncogene Proteins c-fos, pubmed-meshheading:11994125-Rats, pubmed-meshheading:11994125-Rats, Wistar, pubmed-meshheading:11994125-Receptors, Neurokinin-1, pubmed-meshheading:11994125-Receptors, Opioid, mu, pubmed-meshheading:11994125-Substance P, pubmed-meshheading:11994125-Synaptic Transmission
pubmed:year
2002
pubmed:articleTitle
MOR-1-immunoreactive neurons in the dorsal horn of the rat spinal cord: evidence for nonsynaptic innervation by substance P-containing primary afferents and for selective activation by noxious thermal stimuli.
pubmed:affiliation
Spinal Cord Group, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't