Some Currently Neglected Aspects of Cholinergic Function

At the request of the organizers of the XIII International Symposium on Cholinergic Mechanisms, I have selected for review three topics not well represented at the meeting: the synthesis, storage, and release of acetylcholine at cholinergic nerve endings; cholinergic-specific antigens; and neuropeptides as cholinergic co-transmitters. The first topic is illustrated by work with two model systems, the electromotor nerve terminals of the electric ray and the myenteric plexus of the guinea-pig ileum, the second by work with Chol-1, a group of cholinergic-specific gangliosides sialylated on their N-acetylgalactosamine residues, and the third by vasoactive intestinal polypeptide which is a co-transmitter at 70% of cholinergic nerve endings in brain and is also present in both of the model cholinergic systems.