ABSTRACT
The intestine is capable of complex behaviours which allow mixing, propulsion, digestion and absorption of food. The mechanism whereby the intrinsic neurons of the enteric nervous system and the circular smooth muscle coordinate their activities to produce propagated contractions have been the subject of intensive investigations for almost a century. Since the intestine contains a large number of neuroactive substances and an equally large number of receptors for a variety of chemicals, preparations of longitudinal muscle with attached myenteric plexus have been widely used by pharmacologists and therefore have provided detailed information about the effect of drugs on motor neurons of the gastrointestinal tract. The complexity of the chemical coding of enteric neurons mirrors the complexity of the receptors involved in neurogenic intestinal functions. This chapter is intended to review the findings that associate any pharmacologically induced change in enteric nerve activity with the appropriate receptor type or subtype recognized by means of selective agonists and/or antagonists.
