RSK2 Signaling in Medial Habenula Contributes to Acute Morphine Analgesia
| Autor: | André Hanauer, Katia Befort, Solange Pannetier, Emmanuel Darcq, Brigitte L. Kieffer, Claire Gaveriaux-Ruff, Pascale Koebel, Megan K. Mahoney |
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| Rok vydání: | 2012 |
| Předmět: |
Nociception
Cell signaling Narcotic Antagonists Motor Activity Pharmacology Ribosomal Protein S6 Kinases 90-kDa Mice Transduction Genetic Drug tolerance medicine Animals RNA Small Interfering Pain Measurement Mice Knockout Analysis of Variance Habenula Behavior Animal Morphine Naloxone business.industry Drug Tolerance Analgesics Opioid Mice Inbred C57BL Psychiatry and Mental health Opioid Knockout mouse Original Article Signal transduction μ-opioid receptor business Morphine Dependence Signal Transduction medicine.drug |
| Zdroj: | Neuropsychopharmacology. 37:1288-1296 |
| ISSN: | 1740-634X 0893-133X |
| Popis: | It has been established that mu opioid receptors activate the ERK1/2 signaling cascade both in vitro and in vivo. The Ser/Thr kinase RSK2 is a direct downstream effector of ERK1/2 and has a role in cellular signaling, cell survival growth, and differentiation; however, its role in biological processes in vivo is less well known. Here we determined whether RSK2 contributes to mu-mediated signaling in vivo. Knockout mice for the rsk2 gene were tested for main morphine effects, including analgesia, tolerance to analgesia, locomotor activation, and sensitization to this effect, as well as morphine withdrawal. The deletion of RSK2 reduced acute morphine analgesia in the tail immersion test, indicating a role for this kinase in mu receptor-mediated nociceptive processing. All other morphine effects and adaptations to chronic morphine were unchanged. Because the mu opioid receptor and RSK2 both show high density in the habenula, we specifically downregulated RSK2 in this brain metastructure using an adeno-associated-virally mediated shRNA approach. Remarkably, morphine analgesia was significantly reduced, as observed in the total knockout animals. Together, these data indicate that RSK2 has a role in nociception, and strongly suggest that a mu opioid receptor–RSK2 signaling mechanism contributes to morphine analgesia at the level of habenula. This study opens novel perspectives for both our understanding of opioid analgesia, and the identification of signaling pathways operating in the habenular complex. |
| Databáze: | OpenAIRE |
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