Computer analysis of the migrating motility complex of the small intestine recorded in freely moving rats

Myoelectric activity of the small intestine was recorded digitally in fasted, freely moving rats fitted with multiple pairs of electrodes in the antimesenterial smooth muscle. The electrodes were implanted under strict aseptic conditions to safeguard the animal's health and thereby benefit experimental results. As in many other mammalian species, the fasted electrical and mechanical activity of the small intestine in the rat consists of alternating periods of activity and quiescence jointly called the Migrating Motility Complex (MMC). Existing methods for the analysis of small bowel myoelectric activity either integrate spike activity over longer periods of time or describe characteristics of single bursts. We have developed a computer program for fast, automated analysis that distinguishes the three characteristic phases of the MMC. The computer program recognizes periods of varying spike burst frequency and then produces a graphical and numerical output of the length and mean burst frequency of the different phases of each MMC that correlates well with the results of visual evaluation. The techniques used are discussed in relation to existing recording and analysis methods, and specific decisions in the program are motivated. The system will be a useful tool in assessing the effects of drugs, peptides, or stress on small bowel motility.