Expression of neural markers in colonic biopsies from Hirschsprung patients.

<p>A) Full thickness frozen section of aganglionic Hirschsprung bowel showing thickened nerve trunks immunolabeled for the neural crest cell marker p75 (green) and neuronal NOS (red). Note abundance of nerve trunks and fibers in the submucosal region, together with fewer thicker nerve trunks in running through the smooth muscle (C, E). B) Immunolabeling of frozen sections for calretinin expression (red) confirmed presence of ENS in ganglionic gut, and its absence in distal aganglionic gut (C). Antibodies to p75 also stained myenteric ganglia (green) in the frozen sections (B, D). The thickened nerve trunks of aganglionic gut displayed p75 immunoreactivity with very strong immunofluorescence in the perineurium and lower levels of immunoreactivity in the endoneurium (C, E). The glial cell marker S100 was also expressed (red) in ganglia (E) and endoneurium of the thickened nerve trunks of aganglionic gut (E). In contrast to p75 staining, there was no S100 immunoreactivity in the perineurium of the thickened nerve trunks (E). All sections are counterstained with DAPI and are typical of the 12 short segment Hirschprung’s tissues examined. Scale bars: A = 120μm; B—E = 100 μm.