BRAIN FOS EXPRESSION AND INTESTINAL MOTOR ALTERATIONS DURING NEMATODE-INDUCED INFLAMMATION IN THE RAT

Brain-gut interactions and intestinal motility were studied during pul monary and jejunal inflammation induced by Nippostrongylus brasiliensi s. Jejunal electromyographic activity was continuously recorded from d ay 1 before to clay 28 after infection. Expression of c-fos was assess ed in the brain by immunohistochemistry, and myeloperoxidase (MPO) act ivity was determined in lung and intestine on days 1, 7, 14, 21, and 2 8 postinfection. The cyclic intestinal motor pattern was replaced by a n irregular activity from day 4, corresponding to larvae migration to the intestine, to day 14. c-fos was expressed in the caudal nucleus of the solitary tract (NTS) and lateral parabrachial nucleus (LPB) on da y 1 (lung stage of N. brasiliensis) and in the medial part of the NTS, the LPB, and locus ceruleus on day 7. Pulmonary and intestinal MPO ac tivity was increased from days 1 to 21 postinfection. During N. brasil iensis infection, c-fos expression indicates that specific and differe nt brain nuclei are activated at the onset of pulmonary and intestinal inflammation, which is associated with motor disorders.