Suk-Bae Moon, et al. termined by the time between the half-maximal-am- plitude points on the rising phase of consecutive con- tractions (Fig. 2B). Contractions were quantified by calcu- lations of the area above the baseline for each MMCs (area under the curve [AUC]; mN·sec/wave) by Acknowledge software ver. 3.2.6. The direction of MMC propagation was defined as either aboral, oral or bidirectional. Data are expressed as means ± standard error of the mean. Parameters were compared between the control and operated model according to the recording channels with Mann-Whitney test. The proportion of propagation direction was compared between the control and operated model with chi-square test or Fisher’s exact test. P < 0.05 was considered statistically significant. Role of the funding source The sponsor of this study had no involvement in study design, or in the experiments, analysis, and interpretation of data, in the writing of the report, nor in the decision to submit the paper for publication. RESULTS MMCs in control mouse (n = 7) Isolated segment of the ileum exhibited periodic con- tractions that propagated from the proximal to the distal regions of the tissue (Fig. 3). All the recording channels showed relatively regular contractions. Thirty-four MMCs were sampled at each recording channel and were ana- lyzed. The amplitude, duration, interval and AUC of MMCs of each channel are shown in Table 1. Most of the MMCs were noted to propagate in an aboral direction (31/34, 91.1%). Only a few MMCs propagated orally (3/34, 8.9%). Bidirectionally propagating MMCs were not de- tected in the control animals. Partial bypass for 2 weeks (n = 4) Partial bypass model exhibited periodic contractions in channel 1, 2, 3 (proximal to the anastomosis, oral and anal side of the loop, respectively). In channel 4 (distal to the anastomosis), MMCs were either irregular or could not be detected and detailed analysis was not possible (Fig. 4A, 254 Fig. 3. Representative traces of migrating motor complexes (MMCs) recorded from the control mice. Dotted lines show the aboral propagation of the MMCs. B). Twenty MMCs were sampled at each recording chan- nel and analyzed. The amplitude, duration, interval, and AUC of MMCs in each channel are shown in Table 1. Significant changes were noted compared to the con- trol, in every channel except channel 4. The amplitude was attenuated (P = 0.003, 0.009, 0.002 at channel 1, 2, 3, re- spectively), duration was shortened (P = 0.000, 0.000, 0.027 at channel 1, 2, 3, respectively) and the interval was also shortened (P = 0.003, 0.001, 0.005 at channel 1, 2, 3, re- spectively). The mean AUC for each MMC also decreased significantly at each of the recording sites (P = 0.000 at channel 1, 2, and 3). Aborally-propagating MMCs (9/20, 45%) and orally- propagating MMCs (9/20, 45%) were equally noted, and bidirectional MMCs were also observed (2/20, 10%). Compared to the control, the proportion of orally-prop- agating MMCs was significantly increased (P = 0.002). Partial bypass for 4 weeks (n = 4) Similar to the 2-week model, periodic contraction oc- curred only in channel 1, 2, 3 (proximal to the anastomosis, oral and anal side of the loop; Fig. 4C, D). As in the 2-week model, detailed analysis of the MMCs was not possible for channel 4 (distal to the anastomosis). The mean amplitude, thesurgery.or.kr