Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2005-9-5
pubmed:abstractText
In both the spared nerve injury (SNI) and spinal nerve ligation (SNL) rat peripheral neuropathic pain models the presynaptic inhibitory effect of the mu opioid receptor (MOR) agonist (DAMGO) on primary afferent-evoked excitatory postsynaptic currents (EPSCs) and miniature EPSCs in superficial dorsal horn neurons is substantially reduced, but only in those spinal cord segments innervated by injured primary afferents. The two nerve injury models also reduce the postsynaptic potassium channel opening action of DAMGO on lamina II spinal cord neurons, but again only in segments receiving injured afferent input. The inhibitory action of DAMGO on ERK (extracellular signal-regulated kinase) activation in dorsal horn neurons is also reduced in affected segments following nerve injury. MOR expression decreases substantially in injured dorsal root ganglion neurons (DRG), while intact neighboring DRGs are unaffected. Decreased activation of MOR on injured primary afferent central terminals and the second order neurons they innervate may minimize any reduction by opioids of the spontaneous pain mediated by ectopic input from axotomized small diameter afferents. Retention of MOR expression and activity in nearby non-injured afferents will enable, however, an opioid-mediated reduction of stimulus-evoked and spontaneous pain carried by intact nociceptor afferents and we find that intrathecal DAMGO (1000 ng) reduces mechanical hypersensitivity in rats with SNL. Axotomy-induced changes in MOR may contribute to opioid- insensitive components of neuropathic pain while the absence of these changes in intact afferents may contribute to the opioid sensitive components.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0304-3959
pubmed:author
pubmed:issnType
Print
pubmed:volume
117
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
77-87
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:16098668-Analgesics, Opioid, pubmed-meshheading:16098668-Animals, pubmed-meshheading:16098668-Blotting, Northern, pubmed-meshheading:16098668-Disease Models, Animal, pubmed-meshheading:16098668-Electric Stimulation, pubmed-meshheading:16098668-Electrophoretic Mobility Shift Assay, pubmed-meshheading:16098668-Enkephalin, Ala(2)-MePhe(4)-Gly(5)-, pubmed-meshheading:16098668-Enzyme Activation, pubmed-meshheading:16098668-Excitatory Postsynaptic Potentials, pubmed-meshheading:16098668-Extracellular Signal-Regulated MAP Kinases, pubmed-meshheading:16098668-Functional Laterality, pubmed-meshheading:16098668-Immunohistochemistry, pubmed-meshheading:16098668-In Situ Hybridization, pubmed-meshheading:16098668-Male, pubmed-meshheading:16098668-Membrane Potentials, pubmed-meshheading:16098668-Neurofilament Proteins, pubmed-meshheading:16098668-Neurons, pubmed-meshheading:16098668-Pain Measurement, pubmed-meshheading:16098668-Pain Threshold, pubmed-meshheading:16098668-Patch-Clamp Techniques, pubmed-meshheading:16098668-Peripheral Nervous System Diseases, pubmed-meshheading:16098668-Physical Stimulation, pubmed-meshheading:16098668-Rats, pubmed-meshheading:16098668-Rats, Sprague-Dawley, pubmed-meshheading:16098668-Receptors, Opioid, mu, pubmed-meshheading:16098668-Spinal Cord, pubmed-meshheading:16098668-Synapses
pubmed:year
2005
pubmed:articleTitle
Peripheral axonal injury results in reduced mu opioid receptor pre- and post-synaptic action in the spinal cord.
pubmed:affiliation
Neural Plasticity Research Group, Department of Anesthesia and Critical Care, Massachusetts General Hospital and Harvard Medical School, 149 13th Street, Charlestown, Boston, MA 02129, USA.
pubmed:publicationType
Journal Article, Comparative Study, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, N.I.H., Extramural