Acetylcholine activates cerebral interneurons and feeding motor program in Limax maximus.

The cellular and network effects of acetylcholine (ACh) on the control system for feeding in Limax maximus were measured by intracellular recordings from feeding command-like interneurons and whole nerve recordings from buccal ganglion motor nerve roots which normally innervate the ingestive feeding muscles. The buccal ganglion motor nerve root discharge pattern which causes rhythmic feeding movements, termed feeding motor program (FMP), was elicited either by attractive taste solutions applied to the lip chemoreceptors or by ACh applied to the cerebral ganglia. The ability of exogeneous ACh applied to the cerebral ganglia to trigger FMP was blocked by the cholinergic antagonists curare and atropine. If the strength of the lip-applied taste stimulus was in the range 2-3 times threshold, cerebral application of the cholinergic antagonists blocked the ability of lip-applied taste solutions to trigger FMP.