Visceral pain is one of the most clinically relevant types of pain. Nonetheless, research in this area and understanding of mechanisms of visceral nociception lags behind that in somatic pain. Descending modulation of nociceptive processing has been extensively studied in many models of somatic pain. While less is known about the role of descending modulatory influences in nociception of visceral origin, descending pain facilitatory mechanisms have been shown to be important in acute visceral inflammation. The possible relevance of descending pain modulation in the context of a longer-term inflammation of the viscera is unknown. Following injuries to peripheral nerves, a pronociceptive, descending facilitatory drive from the RVM is engaged to maintain long-lasting experimental neuropathic pain. Recently, a new model of pancreatic nociception has been developed which lasts for more than one week. Since descending pain facilitation has been shown to be time-dependent at least in some models of pain the extended time course of this model of visceral nociception appears appropriate for the investigation of the potential role of descending facilitation of sustained visceral nociception.
| Vera-Portocarrero, Louis P; Ossipov, Michael H; King, Tamara et al. (2008) Reversal of inflammatory and noninflammatory visceral pain by central or peripheral actions of sumatriptan. Gastroenterology 135:1369-78 |
| Vera-Portocarrero, Louis P; Yie, Jennifer X; Kowal, Justin et al. (2006) Descending facilitation from the rostral ventromedial medulla maintains visceral pain in rats with experimental pancreatitis. Gastroenterology 130:2155-64 |
