Tags

Type your tag names separated by a space and hit enter

Dorsal horn NK1-expressing neurons control windup of downstream trigeminal nociceptive neurons.
Pain. 2008 Jul 15; 137(2):340-51.PAIN

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 neurokinin 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 neurons 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.

Authors+Show Affiliations

Inserm E216, Neurobiologie de la Douleur Trigéminale, Faculté de Chirurgie Dentaire, 11 Boulevard Charles de Gaulle, 63000 Clermont-Ferrand, France.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

17977663

Citation

Coste, Jérôme, et al. "Dorsal Horn NK1-expressing Neurons Control Windup of Downstream Trigeminal Nociceptive Neurons." Pain, vol. 137, no. 2, 2008, pp. 340-51.
Coste J, Voisin DL, Miraucourt LS, et al. Dorsal horn NK1-expressing neurons control windup of downstream trigeminal nociceptive neurons. Pain. 2008;137(2):340-51.
Coste, J., Voisin, D. L., Miraucourt, L. S., Dallel, R., & Luccarini, P. (2008). Dorsal horn NK1-expressing neurons control windup of downstream trigeminal nociceptive neurons. Pain, 137(2), 340-51.
Coste J, et al. Dorsal Horn NK1-expressing Neurons Control Windup of Downstream Trigeminal Nociceptive Neurons. Pain. 2008 Jul 15;137(2):340-51. PubMed PMID: 17977663.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Dorsal horn NK1-expressing neurons control windup of downstream trigeminal nociceptive neurons. AU - Coste,Jérôme, AU - Voisin,Daniel L, AU - Miraucourt,Loïs S, AU - Dallel,Radhouane, AU - Luccarini,Philippe, Y1 - 2007/10/30/ PY - 2007/07/23/received PY - 2007/08/30/revised PY - 2007/09/19/accepted PY - 2007/11/6/pubmed PY - 2008/9/19/medline PY - 2007/11/6/entrez SP - 340 EP - 51 JF - Pain JO - Pain VL - 137 IS - 2 N2 - 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 neurokinin 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 neurons 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. SN - 1872-6623 UR - https://www.unboundmedicine.com/medline/citation/17977663/Dorsal_horn_NK1_expressing_neurons_control_windup_of_downstream_trigeminal_nociceptive_neurons_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0304-3959(07)00538-6 DB - PRIME DP - Unbound Medicine ER -