Document Detail


TRPM8 mechanism of cold allodynia after chronic nerve injury.
MedLine Citation:
PMID:  18077679     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The cold- and menthol-sensitive receptor TRPM8 (transient receptor potential melastatin 8) has been suggested to play a role in cold allodynia, an intractable pain seen clinically. We studied how TRPM8 is involved in cold allodynia using rats with chronic constrictive nerve injury (CCI), a neuropathic pain model manifesting cold allodynia in hindlimbs. We found that cold allodynic response in the CCI animals was significantly attenuated by capsazepine, a blocker for both TRPM8 and TRPV1 (transient receptor potential vanilloid 1) receptors, but not by the selective TRPV1 antagonist I-RTX (5-iodoresiniferatoxin). In L5 dorsal root ganglion (DRG) sections of the CCI rats, immunostaining showed an increase in the percentage of TRPM8-immunoreactive neurons when compared with the sham group. Using the Ca2+-imaging technique and neurons acutely dissociated from the L5 DRGs, we found that CCI resulted in a significant increase in the percentage of menthol- and cold-sensitive neurons and also a substantial enhancement in the responsiveness of these neurons to both menthol and innocuous cold. These changes occurred in capsaicin-sensitive neurons, a subpopulation of nociceptive-like neurons. Using patch-clamp recordings, we found that membrane currents evoked by both menthol and innocuous cold were significantly enhanced in the CCI group compared with the sham group. By retrograde labeling afferent neurons that target hindlimb skin, we showed that the skin neurons expressed TRPM8 receptors, that the percentage of menthol-sensitive/cold-sensitive/capsaicin-sensitive neurons increased, and that the menthol- and cold-evoked responses were significantly enhanced in capsaicin-sensitive neurons after CCI. Together, the gain of TRPM8-mediated cold sensitivity on nociceptive afferent neurons provides a mechanism of cold allodynia.
Authors:
Hong Xing; Meng Chen; Jennifer Ling; Weihong Tan; Jianguo G Gu
Related Documents :
16045489 - Inhibition of peripheral vanilloid trpv1 receptors reduces noxious heat-evoked response...
16217559 - Construction of a stable cell line uniformly expressing the rat trpv1 receptor.
15813989 - Sensitization of trpv1 by ep1 and ip reveals peripheral nociceptive mechanism of prosta...
12912849 - Capsaicin and menthol in the treatment of itch and pain: recently cloned receptors prov...
2059129 - Clonidine inhibits vesico-sphincter reflexes in patients with chronic spinal lesions.
16469789 - Propriospinal neurons contribute to bulbospinal transmission of the locomotor command s...
2413279 - The influence of cholinergic and adrenergic blockade on the portal release of substance...
18322379 - Distinct functional effects of human 5-ht4 receptor isoforms on beta-amyloid secretion.
20594969 - Corticotropin-releasing factor receptors induce calcium mobilization through cross-talk...
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  The Journal of neuroscience : the official journal of the Society for Neuroscience     Volume:  27     ISSN:  1529-2401     ISO Abbreviation:  J. Neurosci.     Publication Date:  2007 Dec 
Date Detail:
Created Date:  2007-12-13     Completed Date:  2008-01-22     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  8102140     Medline TA:  J Neurosci     Country:  United States    
Other Details:
Languages:  eng     Pagination:  13680-90     Citation Subset:  IM    
Affiliation:
Department of Oral and Maxillofacial Surgery, McKnight Brain Institute and College of Dentistry, University of Florida, Gainesville, Florida 32610, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Capsaicin / analogs & derivatives,  therapeutic use
Cells, Cultured
Chronic Disease
Cold Temperature / adverse effects*
Disease Models, Animal
Female
Ganglia, Spinal
Hyperalgesia / drug therapy,  etiology*,  physiopathology*
Ligation
Male
Menthol / pharmacology
Neurons, Afferent / drug effects
Pain Measurement
Patch-Clamp Techniques
Rats
Rats, Sprague-Dawley
Sciatic Neuropathy / complications,  physiopathology*
Skin / innervation
TRPM Cation Channels / antagonists & inhibitors,  metabolism*
Chemical
Reg. No./Substance:
0/TRPM Cation Channels; 0/Trpm8 protein, rat; 0/capsazepine; 1490-04-6/Menthol; 404-86-4/Capsaicin

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Close homolog of L1 and neuropilin 1 mediate guidance of thalamocortical axons at the ventral telenc...
Next Document:  Synaptic vesicle mobility in mouse motor nerve terminals with and without synapsin.