[Physiologic properties of nicotinic cholinoreceptor neurons of sympathetic ganglia].

The properties of nicotinic acetylcholine receptors (AChRs) of sympathetic neurons are described which determine their function--the generation of transmembrane current in response to the action of ACh. The stoichiometry of the relations between AChR and ACh, the relative potencies of different agonists and binding of alpha-bungarotoxin are determined and used for the characteristic of the recognition centre of the AChR. Two populations of AChRs, synaptic and extrasynaptic, are found different in their mean open channel lifetimes, but similar in their mean channel conductances. The bis-ammonium compounds, specific ganglion-blocking agents, exert two kinds of effects on the AChR: competitive and the noncompetitive (channel-blocking). The latter effect determines the specificity of the blockers.