[Calcium ion modulation of short-term plasticity of the cholinoreceptor membrane of the mollusk neuron].

Repeated iontophoretic acetylcholine applications to the external surface of the plasma membrane of identified Helix neurones elicit a gradual reversible reduction of cholinoreceptors (ChR) sensitivity. Influence on Ca-conductivity of neuronal membrane modifies the dynamics of lowering of ChR sensitivity. Administration of cadmium ions--blockader of Ca-conductivity, slows down and weakens ChR habituation, while Ca-conductivity activation by raising of extracellular Ca2+ content accelerates and deepens the habituation. It is suggested that chemo-controlled Ca-conductivity takes part in regulation of short-term ChR plasticity.