Widespread changes in neurotransmitter expression and number of enteric neurons and interstitial cells of Cajal in lethal spotted mice: an explanation for persisting dysmotility after operation for Hirschsprung's disease?

Gastrointestinal motor dysfunction persists in a large number of children subjected to surgical treatment for Hirschsprung's disease, indicating abnormalities in the remaining intestine. The aim of the study was to detect possible alterations in frequency and topographic distribution of enteric neurons and interstitial cells of Cajal in an experimental model (the lethal spotted mouse displaying a short rectal aganglionosis) for Hirschsprung's disease. Specimens from the intestinal tract from homozygous (aganglionic) and heterozygous (healthy littermates) were examined using histochemistry, in situ hybridization, and immunohistochemistry. In ileum and colon, ie, regions proximal to the aganglionosis, changes in the expression of neuropeptides and neuronal nitric oxide synthase and in the number of enteric neurons and interstitial cells of Cajal could be detected in homozygous versus heterozygous mice. The described changes are suggested to contribute to the dysmotility remaining after surgical resection of the aganglionic segment in Hirschsprung's disease.