The most critical event in chemical cell to cell communications is the conversion of the chemical signal into the primary response of the receiving cell. In the case of cholinergic cell to cell communication, i. e. in cholinergic nerve-nerve and nerve- muscle systems, a single molecule, namely the nicotinic acetyl- choline receptor is responsible for both signal reception and primary response: Through binding of the neurotransmitter acetyl- choline released from the associated nerve ending, the receptor receives the chemical message. Short-lived openings of the recep- tor-integral ion channel...

This workshop was the second of this series held on the island of santorini in the Cycladic Sea. The first one ("Mechanism of Action of the Nicotinic Acetylcholine Receptor," NATO ASI Se ries H, vol. 10) took place in May 1986 and focused on what was at the time the best studied of all neuroreceptors. This second one, held only two years later, demonstrates the im mense progress achieved since then in the field of neurorecep tors and ion channels. Molecular cloning techniques have now made available the primary structures of a whole array of ion channel proteins, and this in turn has shed...