Temporal and spatial rhythmicity of jejunal wall motion in rats

Bouchoucha,; Benard, Michael F.; Dupres,

doi:10.1046/j.1365-2982.1999.00162.x

Cited by 18 publications

(21 citation statements)

References 17 publications

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“…The most abundant motor pattern seen, which was present in all preparations, was made up of small-amplitude circular muscle contractions, which bore a close resemblance to the ripples described in isolated preparations of the colon of several species of laboratory animals (1,15,27). Similar regular shallow contractions have been described in similar spatiotemporal maps in rats and mice (3,4,28). They are believed to arise from slow-wave activity in the smooth muscle cells.…”

Section: Discussionmentioning

confidence: 59%

Neurally mediated propagating discrete clustered contractions superimposed on myogenic ripples in ex vivo segments of human ileum

Kuizenga

Sia

Dodds

et al. 2015

American Journal of Physiology-Gastrointestinal and Liver Physi

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Kuizenga MH, Sia TC, Dodds KN, Wiklendt L, Arkwright JW, Thomas A, Brookes SJ, Spencer NJ, Wattchow DA, Dinning PG, Costa M. Neurally mediated propagating discrete clustered contractions superimposed on myogenic ripples in ex vivo segments of human ileum. Am J Physiol Gastrointest Liver Physiol 308: G1-G11, 2015. First published November 13, 2014; doi:10.1152/ajpgi.00230.2014.-Narrow muscle strips have been extensively used to study intestinal contractility. Larger specimens from laboratory animals have provided detailed understanding of mechanisms that underlie patterned intestinal motility. Despite progress in animal tissue, investigations of motor patterns in large, intact specimens of human gut ex vivo have been sparse. In this study, we tested whether neurally dependent motor patterns could be detected in isolated specimens of intact human ileum. Specimens (n ϭ 14; 7-30 cm long) of terminal ileum were obtained with prior informed consent from patients undergoing colonic surgery for removal of carcinomas. Preparations were set up in an organ bath with an array of force transducers, a fiberoptic manometry catheter, and a video camera. Spontaneous and distension-evoked motor activity was recorded, and the effects of lidocaine, which inhibits neural activity, were studied. Myogenic contractions (ripples) occurred in all preparations (6.17 Ϯ 0.36/min). They were of low amplitude and formed complex patterns by colliding and propagating in both directions along the specimen at anterograde velocities of 4.1 Ϯ 0.3 mm/s and retrogradely at 4.9 Ϯ 0.6 mm/s. In five specimens, larger amplitude clusters of contractions were seen (discrete clustered contractions), which propagated aborally at 1.05 Ϯ 0.13 mm/s and orally at 1.07 Ϯ 0.09 mm/s. These consisted of two to eight phasic contractions that aligned with ripples. These motor patterns were abolished by addition of lidocaine (0.3 mM). The ripples continued unchanged in the presence of this neural blocking agent. These results demonstrate that both myogenic and neurogenic motor patterns can be studied in isolated specimens of human small intestine. small intestine; motor patterns; enteric nervous system; myogenic; neurogenic PROPULSION AND MIXING OF INTESTINAL CONTENTS along the digestive tract are essential for normal digestion. The motor patterns underlying these functions are due to the coordinated contractions and relaxations of the smooth muscle layers of the intestine. The internal circular smooth muscle layer and the external longitudinal smooth muscle layer are controlled by two main mechanisms. Myogenic activity is driven by the nonneural pacemaker cells, the interstitial cells of Cajal. Neurogenic control is mediated by circuits in the enteric nervous system. These two types of activity combine to generate the motor patterns that mix and propel luminal content (14,29). Most of our understanding of these mechanisms has been derived from animal studies. Although the basic functions of the gastrointestinal tract are similar between human and animals, there are si...

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Section: Discussionmentioning

confidence: 59%

Neurally mediated propagating discrete clustered contractions superimposed on myogenic ripples in ex vivo segments of human ileum

Kuizenga

Sia

Dodds

et al. 2015

American Journal of Physiology-Gastrointestinal and Liver Physi

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“…Spatio-temporal maps of intraluminal pressure (PMaps) and intestinal diameter have been successfully used separately in both human and/or experimental animals. The simultaneous development of Dmaps in several laboratories (Bouchoucha et al, 1999; Hennig et al, 1999; Bercik et al, 2000) led to accurate descriptions of the movements of isolated segments of intestine (D'Antona et al, 2001; Gwynne and Bornstein, 2007; Lentle et al, 2008, 2012; Hennig et al, 2010; Dinning et al, 2012a). In human clinical investigations, the development high-resolution spatiotemporal plots of pharyngeal and esophageal pressure (Williams et al, 2001) expanded the diagnostic capabilities of esophageal manometry (Pandolfino et al, 2008, 2009).…”

Section: Discussionmentioning

confidence: 99%

An experimental method to identify neurogenic and myogenic active mechanical states of intestinal motility

Costa¹,

Wiklendt²,

Arkwright³

et al. 2013

Front. Syst. Neurosci.

118

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Excitatory and inhibitory enteric neural input to intestinal muscle acting on ongoing myogenic activity determines the rich repertoire of motor patterns involved in digestive function. The enteric neural activity cannot yet be established during movement of intact intestine in vivo or in vitro. We propose the hypothesis that is possible to deduce indirectly, but reliably, the state of activation of the enteric neural input to the muscle from measurements of the mechanical state of the intestinal muscle. The fundamental biomechanical model on which our hypothesis is based is the “three-element model” proposed by Hill. Our strategy is based on simultaneous video recording of changes in diameters and intraluminal pressure with a fiber-optic manometry in isolated segments of rabbit colon. We created a composite spatiotemporal map (DPMap) from diameter (DMap) and pressure changes (PMaps). In this composite map rhythmic myogenic motor patterns can readily be distinguished from the distension induced neural peristaltic contractions. Plotting the diameter changes against corresponding pressure changes at each location of the segment, generates “orbits” that represent the state of the muscle according to its ability to contract or relax actively or undergoing passive changes. With a software developed in MatLab, we identified twelve possible discrete mechanical states and plotted them showing where the intestine actively contracted and relaxed isometrically, auxotonically or isotonically, as well as where passive changes occurred or was quiescent. Clustering all discrete active contractions and relaxations states generated for the first time a spatio-temporal map of where enteric excitatory and inhibitory neural input to the muscle occurs during physiological movements. Recording internal diameter by an impedance probe proved equivalent to measuring external diameter, making possible to further develop similar strategy in vivo and humans.

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“…The ability to record and display changes in gut diameter over time was significantly improved by the development of spatiotemporal video diameter mapping (5,7,18). This method involves processing video-recorded images of gut tissue in vitro into a map in which gray-scale pixels represent gut diameter at each point along an extended segment.…”

Section: Since the Introduction Of Intraluminal Pressure Recording Bymentioning

confidence: 99%

Temporal relationships between wall motion, intraluminal pressure, and flow in the isolated rabbit small intestine

Dinning

Arkwright

Costa

et al. 2011

American Journal of Physiology-Gastrointestinal and Liver Physi

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Intraluminal manometry is a tool commonly used to record motility in the human digestive tract. The recorded signal results from a combination of factors, including the hydrodynamic pressure transmitted through the intestinal contents due to contraction of the gut wall and the force of the gut wall acting on the sensors in regions of a luminal occlusion. However, the actual relationships between small bowel wall contraction, the measured intraluminal pressure, and the resultant flow have not been directly addressed. Video recording and high-resolution fiber-optic manometry were used to create spatiotemporal video maps of diameter and intraluminal pressure from isolated segments of rabbit small intestine. In the unstimulated gut, longitudinal muscle contractions were the only detectable motor pattern; circular muscle contractions were elicited by distension or erythromycin (1 μM). Longitudinal muscle contractions were not lumen-occlusive, although they caused measurable low-amplitude changes in pressure. Localized nonpropagating circular muscle contractions caused small localized, nonpropagating peaks of intraluminal pressure. Propagating contractions of circular muscle evoked larger, propagating pressure changes that were associated with outflow. Propagating circular muscle contractions often caused dilation of aboral receiving segments, corresponding to "common cavities"; these were propulsive, despite their low intraluminal pressure. The highest-amplitude pressure events were caused by lumen-occlusive circular muscle contractions that squeezed directly against the catheter. These data allow us to define the complex relationships between wall motion, intraluminal pressure, and flow. A strong correlation between circular and longitudinal muscle contraction and intraluminal pressure was demonstrated. Common-cavity pressure events, caused by propulsion of content by circular muscle contractions into a receptive segment, were often of low amplitude but were highly propulsive. Studies of wall motion in isolated preparations, combined with manometry, can assist in interpretation of pressure recordings in vivo.

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Temporal and spatial rhythmicity of jejunal wall motion in rats

Cited by 18 publications

References 17 publications

Neurally mediated propagating discrete clustered contractions superimposed on myogenic ripples in ex vivo segments of human ileum

Neurally mediated propagating discrete clustered contractions superimposed on myogenic ripples in ex vivo segments of human ileum

An experimental method to identify neurogenic and myogenic active mechanical states of intestinal motility

Temporal relationships between wall motion, intraluminal pressure, and flow in the isolated rabbit small intestine

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