Please use this identifier to cite or link to this item: http://hdl.handle.net/1822/49118

TitleThe medullary dorsal reticular nucleus as a relay for descending pronociception induced by the mGluR5 in the rat infralimbic cortex
Author(s)Pereira, Ana Carla David
Sagalajev, Boriss
Wei, Hong
Almeida, Armando
Pertovaara, Antti
Pinto-Ribeiro, Filipa
Keywordsinfralimbic cortex
metabotropic glutamate receptor 5
experimental monoarthritis
pronociception
dorsal reticular nucleus
spinal TRPV1
Issue date4-May-2017
PublisherElsevier
JournalNeuroscience
CitationDavid-Pereira, A., Sagalajev, B., Wei, H., Almeida, A., Pertovaara, A., & Pinto-Ribeiro, F. (2017). The medullary dorsal reticular nucleus as a relay for descending pronociception induced by the mGluR5 in the rat infralimbic cortex. Neuroscience, 349, 341-354
Abstract(s)Metabotropic glutamate receptor 5 (mGluR5) activation in the infralimbic cortex (IL) induces pronociceptive behavior in healthy and monoarthritic rats. Here we studied whether the medullary dorsal reticular nucleus (DRt) and the spinal TRPV1 are mediating the IL/mGluR5-induced spinal pronociception and whether the facilitation of pain behavior is correlated with changes in spinal dorsal horn neuron activity. For drug administrations, all animals had a cannula in the IL as well as a cannula in the DRt or an intrathecal catheter. Heat-evoked paw withdrawal was used to assess pain behavior in awake animals. Spontaneous and heat evoked discharge rates of single DRt neurons or spinal dorsal horn wide-dynamic range (WDR) and nociceptivespecific (NS) neurons were evaluated in lightly anesthetized animals. Activation of the IL/mGluR5 facilitated nociceptive behavior in both healthy and monoarthritic animals, and this effect was blocked by lidocaine or GABA receptor agonists in the DRt. IL/mGluR5 activation increased spontaneous and heat-evoked DRt discharge rates in healthy but not monoarthritic rats. In the spinal dorsal horn, IL/mGluR5 activation increased spontaneous activity of WDR neurons in healthy animals only, whereas heat-evoked responses of WDR and NS neurons were increased in both experimental groups. Intrathecally administered TRPV1 antagonist prevented the IL/mGluR5-induced pronociception in both healthy and monoarthritic rats. The results suggest that the DRt is involved in relaying the IL/mGluR5-induced spinal pronociception in healthy control but not monoarthritic animals. Spinally, the IL/mGluR5-induced behavioral heat hyperalgesia is mediated by TRPV1 and associated with facilitated heat-evoked responses of WDR and NS neurons.
TypeArticle
URIhttp://hdl.handle.net/1822/49118
DOI10.1016/j.neuroscience.2017.02.046
ISSN0306-4522
Publisher versionhttp://www.sciencedirect.com/science/article/pii/S030645221730129X
Peer-Reviewedyes
AccessOpen access
Appears in Collections:ICVS - Artigos em Revistas Internacionais com Referee

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