Migrating Spike Bursts and Electrical Slow Waves in the Cat Colon: Effect of Sectioning

Abstract

Abstract The circular muscle electromyogram was recorded with up to 16 electrodes spaced uniformly along the whole cat colon in vitro before and after complete division of the colon between the electrodes. Before division, the electromyogram of the proximal colon contained slow waves with superimposed short spike bursts, while the distal threefourths of the colon exhibited both slow waves and a periodic prolonged migrating spike burst. Seventy per cent of migrating spike bursts started about the hepatic flexure of the colon and spread aborad; 30% started distally and spread orad. The period of the bursts was 74.3 to 83.0 sec, their duration 26.6 to 35.8 sec, and their velocity, 5.15 ± 2.86 mm per sec aborad and 4.77 ± 2.23 mm per sec orad. The migrating spike bursts were abolished by sectioning of the colon. Before partition, slow wave frequency was 4.5 cycles per min in the most proximal 10% of the colon, and 6.0 cycles per min in the most distal 10%, with intermediate values at intermediate points. After partition, slow wave frequency declined to an average of 1.9 cycles per min, 44% of the control value, in the most proximal 10% of the colon, and rose to an average of 7.3 cycles per min, 121% of the control value, in the most distal 10%.