THE EQUINE TENIAE COLI - AN ELECTROPHYSIOLOGICAL STUDY

Previous morphological studies of the equine teniae coli (intestinal b ands) have shown them to be highly innervated. In this study, EMG elec trodes were placed in the wall of the left ventral colon in order to d etermine whether intestinal bands serve as major conduits of myoelectr ical activity. Specifically, electrodes were implanted in the lateral mesocolic band and the adjacent tenia-free bowel of 6 horses. In 3 of these horses, a 1 cm length of the intestinal band was excised to dete rmine if a lesion of this size would ablate local waves of depolarizat ion. Our results indicate that sequential EMG activity persisted despi te this small, focal excision. The persistence of sequential EMG activ ity might reflect the importance of constantly regenerating stimuli to the intestinal motility of the horse. Whether making similar or somew hat larger lesions in all four teniae of the left ventral colon would more definitively disrupt normal pelvic flexure peristalsis will requi re further research.