Origin and propagation of human gastric slow-wave activity defined by high-resolution mapping

Abstract

Slow waves coordinate gastric motility, and abnormal slow-wave activity is thought to contribute to motility disorders. The current understanding of normal human gastric slow-wave activity is based on extrapolation from data derived from sparse electrode recordings and is therefore potentially incomplete. This study employed high-resolution (HR) mapping to reevaluate human gastric slow-wave activity. HR mapping was performed in 12 patients with normal stomachs undergoing upper abdominal surgery, using flexible printed circuit board (PCB) arrays (interelectrode distance 7.6 mm). Up to six PCBs (192 electrodes; 93 cm(2)) were used simultaneously. Slow-wave activity was characterized by spatiotemporal mapping, and regional frequencies, amplitudes, and velocities were defined and compared. Slow-wave activity in the pacemaker region (mid to upper corpus, greater curvature) was of greater amplitude (mean 0.57 mV) and higher velocity (8.0 mm/s) than the corpus (0.25 mV, 3.0 mm/s) (P < 0.001) and displayed isotropic propagation. A marked transition to higher amplitude and velocity activity occurred in the antrum (0.52 mV, 5.9 mm/s) (P < 0.001). Multiple (3-4) wavefronts were found to propagate simultaneously in the organoaxial direction. Frequencies were consistent between regions (2.83 +/- 0.35 cycles per min). HR mapping has provided a more complete understanding of normal human gastric slow-wave activity. The pacemaker region is associated with high-amplitude, high-velocity activity, and multiple wavefronts propagate simultaneously. These data provide a baseline for future HR mapping studies in disease states and will inform noninvasive diagnostic strategies.

Mitochondrial calcium handling within the interstitial cells of Cajal

“…(55,69) partly inspired this work. Our simulations show depletion frequencies within the range of experimental observations for some SW activity (2,41,53). Observations of a closed PMU may be an artifact of high ICC MT density (68), possibly similar to cardiac cell MT "firewalls" for Ca 2ϩ spark confinement (4,47).…”

Exploring gastrointestinal variables affecting drug and formulation behavior: Methodologies, challenges and opportunities

“…It is thus important to acknowledge the complexities of GI motility as a source of tremendous intrinsic variability that needs further investigation, perhaps linked with higher-level physiology of slow wave propagation that is potentially an underlying phenomenon driving motility but whose exact relationships remain unclear (Myers et al, 2002;O'Grady et al, 2010). c. Colonic manometry The colon represents the distal part of the GI tract and plays an important role in the maintenance of electrolyte and fluid balance, in the metabolism of carbohydrates and bile acids, in the absorption of fatty acids and as a reservoir for feces.…”

The location of pacemakers in the uteri of pregnant guinea pigs and rats

“…The optimal way to identify the location of an electrical pacemaker is to record with large numbers of extracellular electrodes simultaneously. This approach was successful in identifying the location of the pacemaker in the stomach (23,27), but a dominant pacemaking site was not found in the pregnant uterus in the guinea pig (20). In the latter case, this was mainly due to the fact that the organ of the guinea pig was too large, and only a relatively small part of the myometrial wall could be covered and analyzed at a sufficient resolution.…”