Enteric Nervous System: Neural Circuits and Chemical Coding

Abstract

The enteric nervous system (ENS) forms the most complex of intrinsic nerve circuits outside the central nervous system. The large numbers of neurons (?500 million) and its repeating overlapping circuits have made ENS circuitry difficult to disentangle. However, enteric neurons are coded by combinations of markers that give each neuron type a unique signature. Correlation of chemical coding with pharmacological analysis of transmission indicates that individual enteric neurons all use two or more transmitters. In this plurichemical transmission from enteric neurons, some compounds, including acetylcholine, nitric oxide, and vasoactive intestinal polypeptide, have primary transmitter roles. © ..