Interstitial cells of Cajal (ICC) play multiple roles in the gut. they act as pacemaker cells to generate basic electric rhythms for gut motility, such as peristalsis and segmentation. ICC also serve as a interface between the autonomic and enteric nervous systems and smooth muscle. Furthermore, their long processes prompt us to speculate that these cells connect electric excitation in the gut, acting as a syncytium. Interleukin-10 (IL-10) is known to suppress gut immunity by antagonizing interferon-γ. IL-10-deficient mice (IL-10-/-) therefore suffer from chronic inflammatory bowel disease (IBD). These mice are also implicated in prominent anal prolapse, although the underlying mechanisms are unclear. We hypothesize that basal electric activity, including in ICC, may be accelerated in IL-10-/- mice, thus spatiotemporal electrical activity was examined and compared with wild-type (WT) mice (C57BL/6J). WT and IL-10-/- mice were sacrificed by cervical dislocation after deeply anaesthetising with diethyl ether. The ileum was quickly excised, and the whole-muscle layer (5 mm × 20 mm) containing the myenteric plexus was isolated. A microelectrode array (MEA; MED 64 System, Alpha Med Science, Osaka, Japan) was employed to measure spontaneous electric activity in ileal musculatures of both WT and IL-10-/- mice. A set of 8 × 8 field potentials over a ~1 mm2 area was simultaneously recorded with the high-pass filtering of 0.1 Hz. In some experiments, nifedipine (1 μM) and tetrodotoxin (TTX, 250 nM) were applied to predominantly measure ICC electric activity. Power spectrum, auto-correlation and cross-correlation analyses were performed using commercial add-in software (Kyowa Electronic Instruments, Tokyo, Japan). Statistical differences were evaluated by an independent t-test. Spontaneous electric activity was synchronized throughout the recording area in WT mice, while unsynchronized electric activity was frequently observed in IL-10-/- mice. A cross-correlation function was derived in 63 channels other than the centre channel used as the reference. The peak value of cross-correlation was significantly lower in IL-10-/- mice than in WT mice (mean±SD: 0.63±0.14, n=9 vs 0.77±0.06, n=9; P<0.01) in the presence of nifedipine and TTX. The spectral power in the frequency range of 9.4 to 27.0 cpm (Pw9.4-27.0) was estimated in all 64 channels. Pw9.4-27.0 was larger in IL-10-/- mice than in WT mice (0.014±0.024 vs 0.007±0.015 mV2), but there was no statistical significant difference (P=0.48). The frequency of oscillation estimated from auto-correlation was significantly higher in IL-10-/- mice than in WT mice (20.47±3.50 vs 14.96±1.46 cpm; P<0.01). These results suggest that unorganised hyper gut activity may contribute to the ethiology of IBD, for instance, by altering antibacterial factors from epithelial cells.