Brain Fos expression and intestinal motor alterations during nematode-induced inflammation in the rat

Brain-gut interactions and intestinal motility were studied during pulmonary and jejunal inflammation induced by Nippostrongylus brasiliensis . Jejunal electromyographic activity was continuously recorded from day 1 before to day 28 after infection. Expression of c- fos was assessed in the brain by immunohistochemistry, and myeloperoxidase (MPO) activity was determined in lung and intestine on days 1 , 7 , 14 , 21 , and 28 postinfection. The cyclic intestinal motor pattern was replaced by an 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 day 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 activity was increased from days 1 to 21 postinfection. During N. brasiliensis infection, c- fos expression indicates that specific and different brain nuclei are activated at the onset of pulmonary and intestinal inflammation, which is associated with motor disorders.