The transition zone in Hirschsprung's bowel contains abnormal hybrid ganglia with characteristics of extrinsic nerves

Abstract

The aganglionic bowel in short‐segment Hirschsprung's disease is characterized both by the absence of enteric ganglia and the presence of extrinsic thickened nerve bundles (TNBs). The relationship between the TNBs and the loss of enteric ganglia is unknown. Previous studies have described decreasing numbers of ganglia with increasing density of TNBs within the transition zone (TZ) between ganglionic and aganglionic gut, and there is some evidence of spatial contact between them in this region. To determine the cellular interactions involved, we have analysed the expression of perineurial markers of TNBs and enteric ganglionic markers for both neural cells and their ensheathing telocytes across four cranio‐caudal segments consisting of most proximal ganglionic to most distal aganglionic from pull‐through resected colon. We show that in the TZ, enteric ganglia are abnormal, being surrounded by perineurium cells characteristic of TNBs. Furthermore, short processes of ganglionic neurons extend caudally towards the aganglionic region, where telocytes in the TNB are located between the perineurium and nerve fibres into which they project telopodes. Thus, enteric ganglia within the TZ have abnormal structural characteristics, the cellular relationships of which are shared by the TNBs. These findings will help towards elucidation of the cellular mechanisms involved in the aetiology of Hirschsprung's disease.

Stromal Hücrelerin Tarihçesi: İnterstisyel Cajal Hücrelerinden Telositlere - İnsan Telositlerine ve Olası İşlevlerine Kısa Bir Bakış

“…In addition, it is interesting to note that a number of TCs are found to be running parallely and share the same location such as the ICC (30) and presumably work in tandem while aiding to each others functions, especially in regards of motility. The presence and distribution of TCs has been investigated in several GI tract diseases, specifically in Crohn's disease, (31) ulcerative colitis (32) and in the aganglionic area of the Hirschsprung gut (33) where the number of TCs was found to be dramatically reduced or even absent. This loss of TCs may contribute to colonic dysmotility.…”