Structural and functional organisation of the enteric nervous system in the stomach

This report summarises some features of the gastric enteric nervous system in the guinea-pig model. Particular attention has been paid to relations be tween neurochemical properties, electrophysiological and putative function of enteric neurones. (1) Cholinergic and nitrergic neurones form separate n euronal populations. (2) Ascending neurones outnumbered descending ones. (3 ) Transmitter-phenotype and projection were related: cholinergic neurones w ere primarily ascending while nitrergic neurones were mainly descending. (4 ) The neurochemical code, i.e. the transmitter colocalisation, could be rel ated to the function of enteric neurones. Colocalisation of substance P and /or enkephaline in cholinergic neurones was characteristic for ascending ex citatory muscle neurones. Descending inhibitory muscle neurones were nitrer gic often colocalising the neuropeptides neuropeptide Y (NPY) and vasoactiv e intestinal peptide (VIP). In the intrinsic innervation of the gastric muc osa NPY/VIP was abundant and colocalised in ascending cholinergic as well a s descending nitrergic neurones. (5) The vast majority of ascending and des cending interneurones were cholinergic and often colocalised NPY. (6) The m ajority of descending mucosa and descending inhibitory muscle neurones were tonically-firing neurones. Our results revealed the characteristics of som e neural components within the enteric nervous system of the stomach which are involved in modulation of mucosa and muscle functions. It may be conclu ded that muscle and mucosa functions are under the control of the enteric n ervous system which contains distinct populations responsible for motor and secretory activity.