Dorsal horn NK1-expressing neurons control windup of downstream trigeminal nociceptive neurons

Abstract : Windup is a progressive, frequency-dependent increase in the excitability of trigeminal and spinal dorsal horn wide dynamic range (WDR) nociceptive neurons to repetitive stimulation of primary afferent nociceptive C-fibers. Superficial dorsal horn neurok-inin 1 receptor (NK1R)-expressing neurons were recently shown to regulate sensitization of WDR nociceptive neurons through activation of a defined spino-bulbo-spinal loop. However, the windup of WDR nociceptive neurons was not regulated through this loop. In the present study, we sought to identify the alternative circuit activated by dorsal horn NK1Rs that mediates WDR neuron windup. As a model we used the rat spinal trigeminal nucleus, in which the subnucleus oralis (Sp5O) contains a pool of WDR neu-rons that receive their nociceptive C-input indirectly via interneurons located in the medullary dorsal horn (MDH). First, we found that intravenous injection of NK1R antagonists (SR140333 and RP67580) produced a reversible inhibition of Sp5O WDR neuron windup. Second, we anatomically identified in the MDH lamina III a subpopulation of NK1R-expressing local interneurons that relay nociceptive information from the MDH to downstream Sp5O neurons. Third, using microinjections of NK1R antagonists during in vivo electrophysiological recordings from Sp5O WDR neurons, we showed that WDR neuron windup depends on activation of NK1Rs located in the MDH laminae I–III. We conclude that, in contrast to central sensitization that is controlled by a spino-bulbo-spinal loop, Sp5O WDR neuron windup is regulated through a local circuit activated by MDH lamina III NK1Rs.
Type de document :
Article dans une revue
PAIN, Elsevier, 2008, 137 (2), pp.340-351. 〈10.1016/j.pain.2007.09.017〉
Liste complète des métadonnées

Littérature citée [71 références]  Voir  Masquer  Télécharger

https://hal-clermont-univ.archives-ouvertes.fr/hal-01543208
Contributeur : Jérôme Coste <>
Soumis le : mercredi 21 juin 2017 - 23:56:49
Dernière modification le : mardi 17 juillet 2018 - 10:06:01
Document(s) archivé(s) le : vendredi 15 décembre 2017 - 22:21:18

Fichier

Coste J_Pain_2008.pdf
Fichiers produits par l'(les) auteur(s)

Identifiants

Collections

Citation

Jerome Coste, Daniel Voisin, Loïs Miraucourt, Radhouane Dallel, Philippe Luccarini. Dorsal horn NK1-expressing neurons control windup of downstream trigeminal nociceptive neurons. PAIN, Elsevier, 2008, 137 (2), pp.340-351. 〈10.1016/j.pain.2007.09.017〉. 〈hal-01543208〉

Partager

Métriques

Consultations de la notice

133

Téléchargements de fichiers

93