Antral Variation of Murine Gastric Pacemaker Cells Informed by Confocal Imaging and Machine Learning Methods

The Interstitial Cells of Cajal (ICC) are specialized gastrointestinal (GI) pacemaker cells that generate and actively propagate electrophysiological events called slow waves. Slow waves regulate the GI motility necessary for digestion. Several functional GI motility disorders have been associated with depletion in the ICC. In this study, a validated Fast Random Forest (FRF) classification method using Trainable WEKA Segmentation for segmenting the networks of ICC was applied to confocal microscopy images of a whole mount tissue from the distal antrum of a mouse stomach (583 x 3,376 x 133 mu m(3), parcellated into 24 equal image stacks). The FRF model performance was compared to 6 manually segmented subfields and produced an area under the receiver-operating characteristic (AUROC) of 0.95. Structural variations of ICC network in the longitudinal muscle (ICC-LM) and myenteric plexus (ICC-MP) were quantified. The average volume of ICC-MP was significantly higher than ICC-LM at any point throughout the antral tissue sampled. There was a pronounced decline of up to 80% in ICC-LM (from 3,705 mu m(3) to 716 mu m(3)) over a distance of 279.3 mu m, that eventually diminished towards the distal antrum. However, an inverse relationship was observed in ICC-MP with an overall increase of up to 157% (from 59,100 mu m(3) to 151,830 mu m(3)) over a distance of approximately 2 mm that proceeds towards the distal antrum.