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Effects of peripheral inflammation on activation of ERK in the rostral ventromedial medulla.
- Source :
-
Brain research [Brain Res] 2005 Nov 30; Vol. 1063 (2), pp. 151-8. Date of Electronic Publication: 2005 Nov 08. - Publication Year :
- 2005
-
Abstract
- In the present study, the activation of extracellular signal-regulated kinase (ERK) in the rostral ventromedial medulla (RVM) following the injection of complete Freund's adjuvant (CFA) into the rat hindpaw was examined in order to clarify the mechanisms underlying the dynamic changes in the descending pain modulatory system after peripheral inflammation. Phospho-extracellular signal-regulated kinase-immunoreactive (p-ERK-IR) neurons were observed in the nucleus raphe magnus (NRM) and nucleus reticularis gigantocellularis pars alpha (GiA). Inflammation induced the activation of ERK in the RVM, with a peak at 7 h after the injection of CFA into the hindpaw and a duration of 24 h. In the RVM, the number of p-ERK-IR neurons per section in rats killed at 7 h after CFA injection (14.2 +/- 1.7) was significantly higher than that in the control group (4.5 +/- 0.9) [P < 0.01]. At 7 h after CFA injection, about 60% of p-ERK-IR neurons in the RVM were serotonergic neurons. The percentage of RVM serotonergic neurons that are also p-ERK positive in the rats with inflammation (20.5% +/- 2.3%) was seven times higher than that in control rats (2.7% +/- 1.4%) [P < 0.01]. These findings suggest that inflammation-induced activation of ERK in the RVM may be involved in the plasticity in the descending pain modulatory system following inflammation.
- Subjects :
- Adjuvants, Immunologic
Animals
Freund's Adjuvant
Hindlimb
Male
Nociceptors immunology
Pain immunology
Pain physiopathology
Rats
Rats, Sprague-Dawley
Extracellular Signal-Regulated MAP Kinases metabolism
Inflammation physiopathology
MAP Kinase Signaling System immunology
Medulla Oblongata immunology
Medulla Oblongata physiopathology
Subjects
Details
- Language :
- English
- ISSN :
- 0006-8993
- Volume :
- 1063
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Brain research
- Publication Type :
- Academic Journal
- Accession number :
- 16288729
- Full Text :
- https://doi.org/10.1016/j.brainres.2005.09.057