Myoelectrical activity of the gastrointestinal tract of sheep analysed by computer

Effects of 5-Hydroxytryptamine Agonists on Myoelectric Activity of the Forestomach and Antroduodenal Area in Sheep

“…This higher sensitivity of the antroduodenal area to serotonergic agents, compared with that of the forestomach, is in agreement with the independent motility coordination in both ruminant digestive areas (Ruckebusch 1989). A slight reduction in omasal activity associated with the spontaneous duodenal phase 111 has, however, been reported, and a related delay in reticuloruminal cycles has also been occasionally observed in sheep (Plaza et al 1996~). This forestomach hypomotility pattern is also observed with high doses of serotonergic agents.…”

Evidence for the involvement of 5‐HT4 receptors in the 5‐hydroxytryptamine‐induced pattern of migrating myoelectric complex in sheep

“…However, we have recorded a jejunal stimulation just before some spontaneous phase III periods and found that their propagation rate was diminished, as occurs with those MMC‐like patterns induced by high doses of 5‐HT. Similarly, inhibition of forestomach motility has also occasionally been recorded in association with the spontaneous duodenal phase III in sheep (Plaza et al , 1996d). Taken together, these results suggest that in some spontaneous cycles, endogenous 5‐HT could be released at a rate slightly higher than that needed to evoke a MMC pattern.…”

“…The myoelectric activity was integrated as the sum of the absolute values of the signal amplitude minus the background value (5% of the maximal signal amplitude) over 1 min intervals. Data of integrated myoelectric activity were expressed as a percentage relative to the mean value of the control period (phase II) as previously described (Plaza et al , 1996d). In order to simplify the results, data showed in this work correspond to those obtained from duodenum at 50 cm from the pylorus and from jejunum at 5 m from the ligament of Treitz.…”

Myoelectric activity of the spiral colon in dairy cows

“…Furthermore, use of a computer-based spike-counting program for analysis of spike frequency, spike duration, and percentage of recording time with spike activity in phases I and II reduced the amount of time required to obtain numeric values for these variables while providing values that were more reliable, because they were based on objective criteria (preset threshold values) and not on subjective visual evaluation by the investigators. 19,23 Analysis started with visual evaluation of the data and description of the temporal association between myoelectric activity in the spiral colon and more proximal portions of the intestines (Fig 3 and 4). Similar to other segments of the gastrointestinal tract, motility of the spiral colon is characterized by cyclic recurrence of distinct patterns of myoelectric activity.…”