Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society
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Neurogastroenterol. Motil. · Jun 2010
Day-to-day reproducibility of prolonged ambulatory colonic manometry in healthy subjects.
Although colonic manometry provides useful information regarding colonic physiology, considerable variability has been reported both for regional motility and manometric patterns. Whether colonic manometry is reproducible is not known. ⋯ Colonic manometry findings were generally reproducible, particularly for the assessment of key physiologic changes, such as meal-induced gastrocolonic, HAPC, and waking responses.
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Neurogastroenterol. Motil. · May 2010
ReviewRole of spinal cord glia in the central processing of peripheral pain perception.
The discovery that glial activation plays a critical role in the modulation of neuronal functions and affects the spinal processing of nociceptive signalling has brought new understanding on the mechanisms underlying central sensitization involved in chronic pain facilitation. Spinal glial activation is now considered an important component in the development and maintenance of allodynia and hyperalgesia in various models of chronic pain, including neuropathic pain and pain associated with peripheral inflammation. In addition, spinal glial activation is also involved in some forms of visceral hyperalgesia. ⋯ We discuss the signalling pathways engaged in central glial activation, including stress pathways, and the neuron-glia bidirectional relationships involved in the modulation of synaptic activity and pain facilitation. In this expanding field of research, the characterization of the mechanisms by which glia affect spinal neuro-transmission will increase our understanding of central pain facilitation, and has the potential for the development of new therapeutic agents for common chronic pain conditions.
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Neurogastroenterol. Motil. · May 2010
5-HT(2B) receptors modulate visceral hypersensitivity in a stress-sensitive animal model of brain-gut axis dysfunction.
Irritable bowel syndrome (IBS) is associated with an enhanced perception to visceral stimuli and exaggerated stress response. The serotonergic neurotransmitter system has been strongly implicated as a key player in the manifestation of IBS symptomatology including visceral hypersensitivity. However the role of 5-HT(2B) receptors in visceral pain, although speculated, is currently unclear. Thus we assessed the impact of a selective 5-HT(2B) receptor antagonist, RS-127445, on visceral hypersensitivity in a model of brain gut axis dysfunction the Wistar Kyoto (WKY) rat. ⋯ Taken together, blockade of 5-HT(2B) receptors offers an exciting novel therapeutic target for pain relief in stress-related gastrointestinal disorders such as IBS.
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Neurogastroenterol. Motil. · Apr 2010
Opioid-induced bowel disorders and narcotic bowel syndrome in patients with chronic non-cancer pain.
Opioids are used increasingly in the management of moderate-to-severe chronic non-cancer pain (CNCP). Opioid-induced bowel disorders (OBD) markedly impact health-related quality of life (HRQoL) and frequently limit medically indicated opioid pharmacotherapy. We assessed the risk factors, and effect of OBD on HRQoL in CNCP patients. We also estimated the likely prevalence of narcotic bowel syndrome (NBS). These effects have been reported in cancer patients but not in CNCP previously. ⋯ Bowel disorders including chronic abdominal pain and NBS are common in patients taking opioids for CNCP. Decreased HRQoL in patients with CNCP is driven by chronic abdominal pain.
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Neurogastroenterol. Motil. · Mar 2010
Heightened central affective response to visceral sensations of pain and discomfort in IBS.
BACKGROUND Typically, conventional functional imaging methods involve repeated exposures to sensory stimulation. In rectal distension (RD) studies that involve multiple distensions, however, it is difficult to disambiguate the central response to RD from pathological alterations in peripheral neural responses associated with relaxation and accommodation of the rectum. METHODS This study addressed potential confounders found in previous imaging studies by collecting functional magnetic resonance imaging studies (fMRI) data during a single slow ramp-tonic distension paradigm and analysing fMRI signal changes using independent component analysis. ⋯ In addition, the failure by IBS patients to down-regulate activity within ventral medial prefrontal and the posterior cingulate/precuneus regions was suggestive of reduced sensitivity to somatic changes and delayed shifts away from rest in ;default network' activity patterns. Controls showed heightened activation of the thalamus, striatal regions and dorsolateral prefrontal cortex suggesting greater arousal and salience-driven sustained attention reactions and greater modulation of affective responses to discomfort and pain. CONCLUSION&INFERENCES This work points to alterations in the central response to visceral pain and discomfort in IBS, highlighting diminished modulation and heightened internalization of affective reactions.