Changes in the intestinal spike activity upon electrical stimulation of the intrinsic nervous system
Atanassova, E.; Papasova, M.; Velkova, V.
Acta Physiologica et Pharmacologica Bulgarica 4(1): 3-10
1978
ISSN/ISBN: 0323-9950 PMID: 726913 Document Number: 129501
Chronic experiments on dogs were performed using Ag lamellar electrodes for stimulation, implanted on the duodenal wall at about 8 cm from sphincter pylori. Ag bipolar ball-shaped electrodes (3) were implanted below and above the stimulation electrodes to record the electrical activity of the intestinal muscle wall. The intrinsic nervous system of the intestine was stimulated with rectangular impulses with frequencies of 5-15 cps and and 30-50 cps, duration of the implulses 1 ms and amplitude 5-15 V. Brief stimulations (1-2 min) as well as longer stimulations (20-30 min) were applied. The more prolonged stimulations were fractionated in 2 min stimulations followed by 2 min intervals. Brief stimulations with frequency of 5-15 cps were used to induce spike activity during the stimulation. More prolonged fractionated stimulations wtih the same frequency were used to evoke spike activity which obliterates 1 quiescent period, the 1st phase of the myoelectrical complex. Brief stimuli with frequency 50 cps inhibit the existing spike activity in the duodenal region below the stimulating electrodes. Prolonged stimulation with the same frequency inhibits the development of the 3rd phase of the myoelectrical complex. In its place remains the 2nd phase until the appearance of the subsequent 1st phase or the rest phase. Electrical stimulation of the intrinsic nervous system may influence the myoelectrical complex by inhibition or evoking the spike activity from the smooth-muscle wall of the small intestine.