In a model of abdominal surgery, which consisted of cecal manipulation and induces postoperative ileus in rats, we studied c-fos protein expression in the nucleus of the solitary tract (NTS), the spinal cord and dorsal root ganglia. Abdominal surgery resulted in a significantly higher number of c-fos protein immunoreactive cells in the NTS compared with controls but not in dorsal root ganglia and resulted in only a few scattered cells in the spinal cord. Neurons expressing c-fos protein were concentrated in NTS regions where cecal afferents terminate. These findings support the hypothesis that sensory vagal pathways partly mediate abdominal surgery-induced postoperative ileus.