Telemetric Small Intestinal Motility Recording in Awake Rats

INTRODUCTION: Ideally, gastrointestinal motility recording should be done in freely moving, stress-free animals. However, no such method is currently available for rats. METHODS: Two NiCr electrodes were sutured to the jejunum and connected to an implantable electromyographic (EMG) transmitter in rats. EMG signals were radio-transmitted to a receiver placed at the bottom of the rats' home cages. RESULTS: Fasting and postprandial jejunal EMG signals could be detected by telemetry. Phase III contractions of the MMC were easy to identify visually and occurred at a rate of about 4.8 per hour. Feeding disrupted the phasic contraction pattern 15 min after the start of food intake and lasted for 2 h. The motility index (MI, area under the curve) was calculated and increased postprandially. CONCLUSION: Telemetric transmission of rat gastrointestinal EMG signals is feasible and results are comparable to those given in the literature.