Jump to main content
US EPA
United States Environmental Protection Agency
Search
Search
Main menu
Environmental Topics
Laws & Regulations
About EPA
Health & Environmental Research Online (HERO)
Contact Us
Print
Feedback
Export to File
Search:
This record has one attached file:
Add More Files
Attach File(s):
Display Name for File*:
Save
Citation
Tags
HERO ID
1511842
Reference Type
Journal Article
Title
Engagement of descending inhibition from the rostral ventromedial medulla protects against chronic neuropathic pain
Author(s)
De Felice, M; Sanoja, R; Wang, R; Vera-Portocarrero, L; Oyarzo, J; King, T; Ossipov, MH; Vanderah, TW; Lai, J; Dussor, GO; Fields, HL; Price, TJ; Porreca, F
Year
2011
Is Peer Reviewed?
1
Journal
Pain
ISSN:
0304-3959
EISSN:
1872-6623
Volume
152
Issue
12
Page Numbers
2701-2709
Language
English
PMID
21745713
DOI
10.1016/j.pain.2011.06.008
Web of Science Id
WOS:000296916600009
URL
http://
://WOS:000296916600009
Exit
Abstract
A puzzling observation is why peripheral nerve injury results in chronic pain in some, but not all, patients. We explored potential mechanisms that may prevent the expression of chronic pain. Sprague Dawley (SD) or Holtzman (HZ) rats showed no differences in baseline sensory thresholds or responses to inflammatory stimuli. However, spinal nerve ligation (SNL)-induced tactile allodynia occurred in approximately 85% of SD and 50% of HZ rats, respectively. No apparent differences were observed in a survey of dorsal root ganglion or spinal neuropathic markers after SNL regardless of allodynic phenotype. SNL-induced allodynia was reversed by administration of lidocaine within the rostral ventromedial medulla (RVM), a site that integrates descending pain modulation via pain inhibitory (ie, OFF) and excitatory (ie, ON) cells. However, in SD or HZ rats with SNL but without allodynia, RVM lidocaine precipitated allodynia. Additionally, RVM lidocaine produced conditioned place preference in allodynic SD or HZ rats but conditioned place aversion in nonallodynic HZ rats. Similarly, RVM U69,593 (kappa opioid agonist) or blockade of spinal α(2) adrenergic receptors precipitated allodynia in previously nonallodynic HZ rats with SNL. All rats showed an equivalent first-phase formalin responses. However, HZ rats had reduced second-phase formalin behaviors along with fewer RVM OFF cell pauses and RVM ON cell bursts. Thus, expression of nerve injury-induced pain may ultimately depend on descending modulation. Engagement of descending inhibition protects in the transition from acute to chronic pain. These unexpected findings might provide a mechanistic explanation for medications that engage descending inhibition or mimic its consequences.
Keywords
Word; Any order
Tags
IRIS
•
Formaldehyde
Nervous system effects
Found
Database search results
Web of Science
Screened
Title/abstract
Non-relevant exposure paradigm
Retroactive RIS import
Pre2013
Merged Litsearch Results 100912
Merged LitSearch Results ToxNet 101012
Merged LitSearch Additions 86 Reviews SCREEN
Web of Science Search 100412
2013
HCHON tox Ref Identification 022713
Home
Learn about HERO
Using HERO
Search HERO
Projects in HERO
Risk Assessment
Transparency & Integrity