Electrical activity of the ovine jejunum and changes due to disturbances

Spike potential activity of the jejunum was recorded from chronically implanted electrodes in conscious sheep. The activity was summed at 20-sec intervals before, during, and after induction of diarrhea, small-bowel obstruction, and after nerve section. Sheep on a normal diet regimen exhibited migrating myoelectric complexes at a frequency of 18/24 hr. These complexes displayed irregular and regular activities which occupied 67% of the recording time. A common pattern observed during the manipulations was disorganization of the motor profile. The normal pattern was replaced by continuous spiking activity followed in many cases by total quiescence. After vagotomy the complexes still occurred but the duration of irregular spiking activity was decreased. These experiments suggest that the migrating myoelectric complex acts as a regulating factor and suggests that the ratio of irregular to regular activity is dependent on the influence of extrinsic nerves.