Prenatal development of the myenteric plexus in the human fetal small intestine

Abstract

The enteric nervous system is large, complex and independent of the central nervous system. Its neuralcrest-derived precursors migrate along defined pathways to colonize the bowel. It has been established that signalling molecules produced by the developing neurons and the mesenchyma of the gut wall play a critical role in the development of the mammalian enteric nervous system. Recent studies have further characterized the roles of the different cellular and molecular elements that are critical for enteric ganglia formation. The application of modern neuroanatomical techniques revealed that the enteric nervous system contains a considerable number of neuronal subpopulations. Most of our knowledge concerning the functional features of the enteric neurons, e.g. chemical coding, neuronal connectivity and electrophysiological behaviour, was derived from studies of the guinea-pig small intestine. In light of the interspecies differences, comparison of the findings on different species is mandatory. Consequently, the investigation of human fetal material is necessary in order to estab-lish the basic rules of the development of the human enteric nervous system and to find the time relation between the morphological and functional maturation, thereby permitting an understanding of the causes of congenital malformation leading to misfunction of the gastrointestinal system.