Altered tryptophan hydroxylase 2 expression in enteric serotonergic nerves in Hirschsprung’s-associated enterocolitis

Figure 1 Confocal micrograph series demonstrating pattern of tryptophan hydroxylase-2 expression in the myenteric plexus of the colon. There is almost no HuD or TPH2 immunofluorescence seen in aganglionic colon in HSCR in (A), while there is clear co-expression (arrow head) in the nerve cell bodies in (B). While TPH2 and anoctamin-1 (ANO1) are not co-expressed in (C), the interstitial cells of Cajal (ICC) fibers form a dense network around TPH2-immuno-positive ganglia. TPH2 was co-expressed with PDGFRα cell bodies in the myenteric plexus, seen in (D). TPH2: Tryptophan hydroxylase-2; HSCR: Hirschsprung’s disease.