Please use this identifier to cite or link to this item: http://hdl.handle.net/1822/8816

TitleEnhanced pronociception by amygdaloid group I metabotropic glutamate receptors in nerve-injured animals
Author(s)Ansah, Osei B.
Gonçalves, Leonor
Almeida, Armando
Pertovaara, Antti
KeywordsAmygdala
Neuropathic pain
Rostroventromedial medulla
Metabotropic glutamate receptor
Emotion
Descending pathways
Issue dateMar-2009
PublisherElsevier
JournalExperimental Neurology
Citation"Experimental Neurology." ISSN 0014-4886. 216:1 (Mar. 2009) 66-74.
Abstract(s)Peripheral neuropathy has been associated with structural and functional changes of the amygdala, a key player in emotions. Here we study whether peripheral neuropathy influences pain regulation by the amygdala. For this purpose, we determined discharge rates of presumably pro- and antinociceptive pain-regulatory neurons in the rostral ventromedial medulla (RVM) following microinjection of various glutamatergic compounds into the central nucleus of the amygdala. RVM neurons were recorded in pentobarbitone-anesthetized rats with a peripheral nerve injury or sham-operation. In a separate behavioral experiment, we determined whether the influence of amygdaloid administration of a glutamatergic compound on affective pain-related behavior, as assessed by an aversive place-conditioning test, is changed by neuropathy. While glutamate or an NMDA receptor antagonist in the amygdala failed to induce marked changes in discharge rates of RVM cells, amygdaloid administration of DHPG, a group I metabotropic glutamate receptor (mGluR) agonist acting on mGluR1 and mGluR5, increased discharge rates of presumably pronociceptive RVM ON-cells in nerve-injured but not sham-operated animals. This pronociceptive effect of DHPG was reversed by MPEP (mGluR5 antagonist) and CPCCOEt (mGluR1 antagonist). CHPG, an mGluR5 agonist, failed to influence ONcell activity and DHPG failed to influence activity of presumably antinociceptive RVM OFF-cells. Amygdaloid administration of DHPG increased and that of CPCCOEt decreased affective pain-related behavior in nerve-injured animals. The results suggest that following nerve injury, the amygdaloid group I mGluR, particularly subtype mGluR1, has an enhanced pronociceptive effect providing a potential mechanism for emotional enhancement of pain in peripheral neuropathy.
TypeArticle
URIhttp://hdl.handle.net/1822/8816
DOI10.1016/j.expneurol.2008.11.005
ISSN0014-4886
Publisher versionhttp://www.sciencedirect.com/
Peer-Reviewedyes
AccessOpen access
Appears in Collections:ICVS - Artigos em Revistas Internacionais com Referee

Files in This Item:
File Description SizeFormat 
Exp Neurol, in press.pdf415,23 kBAdobe PDFView/Open

Partilhe no FacebookPartilhe no TwitterPartilhe no DeliciousPartilhe no LinkedInPartilhe no DiggAdicionar ao Google BookmarksPartilhe no MySpacePartilhe no Orkut
Exporte no formato BibTex mendeley Exporte no formato Endnote Adicione ao seu ORCID