Sikandar, S; Bannister, K; Dickenson, AH; (2012) Brainstem facilitations and descending serotonergic controls contribute to visceral nociception but not pregabalin analgesia in rats. Neuroscience Letters , 519 (1) 31 - 36. 10.1016/j.neulet.2012.05.009.

Preview

PDF 1354304.pdf Download (861kB)

Abstract

Pro-nociceptive ON-cells in the rostral ventromedial medulla (RVM) facilitate nociceptive processing and contribute to descending serotonergic controls. We use RVM injections of neurotoxic dermorphin-saporin (Derm-SAP) in rats to evaluate the role of putative ON-cells, or μ-opioid receptor-expressing (MOR) neurones, in visceral pain processing. Our immunohistochemistry shows that intra-RVM Derm-SAP locally ablates a substantial proportion of MOR and serotonergic cells. Given the co-localization of these neuronal markers, some RVM ON-cells are serotonergic. We measure visceromotor responses in the colorectal distension (CRD) model in control and Derm-SAP rats, and using the 5-HT(3) receptor antagonist ondansetron, we demonstrate pro-nociceptive serotonergic modulation of visceral nociception and a facilitatory drive from RVM MOR cells. The α(2)δ calcium channel ligand pregabalin produces state-dependent analgesia in neuropathy and osteoarthritis models relating to injury-specific interactions with serotonergic facilitations from RVM MOR cells. Although RVM MOR cells mediate noxious mechanical visceral input, we show that their presence is not a permissive factor for pregabalin analgesia in acute visceral pain.

Download activity - last month

Export as CSVXMLJSON

Download activity - last 12 months

Export as JSONXMLCSV

Downloads by country - last 12 months

Export as XMLJSONCSV

Archive Staff Only

View Item