Methods for High-Resolution Electrical Mapping in the Gastrointestinal Tract

Abstract

Over the last two decades, high-resolution (HR) mapping has emerged as a powerful technique to study normal and abnormal bioelectrical events in the gastrointestinal (GI) tract. This technique, adapted from cardiology, involves the use of dense arrays of electrodes to track bioelectrical sequences in fine spatiotemporal detail. HR mapping has now been applied in many significant GI experimental studies informing and clarifying both normal physiology and arrhythmic behaviors in disease states. This review provides a comprehensive and critical analysis of current methodologies for HR electrical mapping in the GI tract, including extracellular measurement principles, electrode design and mapping devices, signal processing and visualization techniques, and translational research strategies. The scope of the review encompasses the broad application of GI HR methods from in-vitro tissue studies to in-vivo experimental studies, including in humans. Controversies and future directions for GI mapping methodologies are addressed, including emerging opportunities to better inform diagnostics and care in patients with functional gut disorders of diverse etiologies.

Dynamic slow‐wave interactions in the rabbit small intestine defined using high‐resolution mapping

“…ICC generate cellular pacemaker potentials that are regenerative and propagate through the ICC network and to the smooth muscle cells . The aggregate of voltage potentials can be recorded on the extracellular serosal surface . In this study, high‐resolution mapping was applied along the length of the rabbit small intestine to define slow‐wave characteristics in spatiotemporal detail.…”

“…5,6,34 The aggregate of voltage potentials can be recorded on the extracellular serosal surface. 10,12 In this study, high-resolution mapping was applied along the length of the rabbit small intestine to define slow-wave characteristics in spatiotemporal detail. Diamant et al explained a critical phenomenon of the intestinal slow-wave activity where their result indicated the frequency of slow waves decreased progressively along the small intestine.…”

“…Extracellular recordings from the serosal surface are a result of the variations in the underlying membrane potentials. The extracellular recordings record an aggregate potential from the tissue located next to the electrode and can be approximated as the second derivative of the membrane potentials . Using a limited number of electrodes spaced along the length of the intestine, it was hypothesized that there was a single slow‐wave pacemaker in the proximal duodenum driving slow waves to the ileum .…”

“…the tissue located next to the electrode and can be approximated as the second derivative of the membrane potentials. 10,12 Using a limited number of electrodes spaced along the length of the intestine, it was hypothesized that there was a single slow-wave pacemaker in the proximal duodenum driving slow waves to the ileum. 13,14 Across the intact small intestine, investigators observed a decline in slow-wave frequency, [15][16][17] which was in line with the initial observations of the variations of the contractile rhythm between the proximal and distal ends.…”

“…The introduction of high-resolution (HR) multi-electrode mapping has offered an improved platform for acquiring intestinal slow waves from a large number of electrodes. 12,22 Lammers et al 23 were the first to perform HR mapping in the small intestine of the rabbit. The term pacemaker was used to describe the origin of slow-wave activity in the duodenum recorded extracellularly.…”