STRUCTURAL ORGANIZATION AND NEUROPEPTIDE DISTRIBUTION IN THE MAMMALIAN ENTERIC NERVOUS-SYSTEM, WITH SPECIAL ATTENTION TO THOSE COMPONENTS INVOLVED IN MUCOSAL REFLEXES

Gastrointestinal events such as peristalsis and secretion/absorption p rocesses are influenced by the enteric nervous system, which is capabl e of acting largely independently from other parts of the nervous syst em. Several approaches have been used to further our understanding of the underlying mechanisms of specific enteric microcircuits. Apart fro m pharmacological and physiological studies, the deciphering of the ch emical coding of distinct morphological and functional enteric neuron classes, together with a detailed analysis of their projections by the application of immunocytochemistry, of tracing, and of denervation te chniques, have substantially contributed to our knowledge. In view of existing interspecies and regional differences, it is of major importa nce to expand our knowledge of the enteric nervous system in mammals o ther than the guinea-pig, the most commonly used experimental animal i n this research area. This will increase our chances of finding a vali d model, from which well-founded extrapolations can be made regarding the precise function of distinct enteric neuron types regulating motil ity and ion transport in the human gastrointestinal tract. (C) 1997 El sevier Science Inc.