Autonomic nerves in rectum and colon in Hirschsprung's disease. A cholinesterase and catecholamine histochemical study.

The autonomic nervous system innervates normal bowel in a complicated manner. Study of these nerves has been facilitated by histochemical techniques which enable separate identification of adrenergicand acetylcholinesterase (AChE)-containing nerves. The latter are usually considered to be cholinergic, and while their presence in the muscle layers of the bowel wall is well known, little attention has been paid to their detailed distribution. It has usually been considered that the adrenergic nerves are also distributed directly to the muscle layers, but recent studies by Norberg (1964), Jacobowitz (1965), and Baumgarten (1967) have shown that these nerves are mainly associated with the myenteric ganglia. The ganglion cells themselves do not contain catecholamines, but possess variable amounts of AChE-activity (Koelle, 1955; Cauna et al., 1961; Gunn, 1968). In a classical case of Hirschsprung's disease, an undilated rectum is found to be devoid of ganglion cells on routine histology, though large nerve trunks are present. More proximal bowel appears normal. Recent studies of the morphology of nerves in aganglionic bowel from Hirschsprung's disease have been reported by Smith (1967) using silver staining, and by Ehrenpreis, Norberg, and Wirsen (1968) using catecholamine fluorescence. These workers suggested that the muscle layers themselves were virtually denervated, and that unopposed muscle activity was responsible for the contracted appearance of affected bowel. Meier-Ruge (1968), on the other hand, as a result of cholinesterase studies, suggested that the contraction was due to an increase in muscular